There are a million things you need to correct in order to even try to get them to grow, and most likely they won't reach near full potential, they didn't get proper nutrition,
UVB light, UVA light, temperatures, calcium supplementation, etc. during their baby/juvenile/subadult periods when growth occurs normally. But they can still have good lives if you properly house and feed them, though I guarantee that they also most likely are suffering from Metabolic Bone Disease and you need to focus on trying to remedy that as well.
Could you please post photos of both of them, their enclosure and lights, and then please answer the following questions so that we can tell you what changes need to be made and give any advice we can to you (it's a lot of questions, I know, but it is all information that we need to know in order to access what's going on:
GENERAL INFORMATION ABOUT YOUR BEARDIE:
1.)How old is your beardie?
2.)Is your beardie male, female, or are you unsure?
3.)How long is your beardie from the tip of his snout to the end of his tail?
4.)How many grams does your beardie weigh?
5.)Have you had him since he was a hatchling? If not, at what age did you acquire them? How long have you had them?
6.)If you acquired your beardie from their previous owner (was a rescue, adoptee, rehome, etc.), were they in good health at that point? Did they have proper care from their prior owner?
ENCLOSURE:
1.)What size, type, and brand of enclosure are they each in (dimensions; aquarium, EXO Terra, or Custom; and glass, wood, etc.)? If you have more than one beardie, are they kept separately?
2.)What substrate do you have lining the bottom of your beardie's enclosure?
3.)How often do you change the substrate in the bottom of the enclosure? How often do you clean your beardie's bowls? How often do you clean their entire enclosure? What do you use to clean the bowls, enclosure, etc.?
LIGHTING:
1.)What brand, model, wattage, type (tube/regular lightbulb shape, or coil bulb) and size in inches (if a tube)
UVB light do each of them have? How far are their main basking spots from their UVB lights? If a long tube UVB, did you remove any plastic protective covers that came with the fixtures that were over the bulb? Are their UVB lights inside their enclosures, or are they sitting on top of a mesh or glass lid?
2.)What brand, model, wattage, and type (regular lightbulb or coil bulb) are each of their basking bulbs? How many basking bulbs do you have on each enclosure? What color are their basking bulbs (bright white, clear, soft white, yellow, blue, red, etc.)? Do you use any separate source of heat at nighttime? If so, are they bulbs that produce light, or Ceramic Heat Emitters that produce no light? How far away are their basking bulbs from their main basking spots?
3.)How many hours per day are your beardie's UVB and basking lights on?
TEMPERATURES:
1.)What are the 3 main temperatures in each of their enclosures (Hot Side, Cool Side, and Main Basking Spot)?
2.)What are you using to measure these temperatures (stick on thermometer, round gauge thermometer, digital thermometer with a probe on a wire, IR Temperature Gun, etc.)?
3.)If you are using a digital thermometer with a probe on a wire, are you allowing the probe to sit for 20-30 minutes in the testing spot before reading the temperature?
DAILY DIET and SUPPLEMENTATION:
1.)What live insects(s) do you feed them daily as their STAPLE INSECTS (their staple proteins)? What, if any, live insects do you not feed as a daily staple feeder but give to them as occasional treats? How many times a week do you feed them these treat insects? How many of these treat insects do you feed them at one time?
2.)How many live STAPLE insects do they eat in one sitting, or how long a period do you allow them to eat unlimited STAPLE insects in one sitting?
3.)How many live STAPLE insect feedings do you allow each day?
4.)Do you dust their live STAPLE feeders in a calcium powder? If so, what brand of calcium powder do you use to dust their live STAPLE insects in? Does it contain vitamin D3?
5.)How many times per week do you dust their live STAPLE insects in this calcium powder? If you allow multiple live feeding sessions per day, during how many of those live feeding sessions do you dust the insects in this calcium powder?
6.)Do you use a Multivitamin powder to dust their live STAPLE insects in? If so, what brand and type of Multivitamin powder do you use?
7.)How many days per week do you dust their live feeder insects in this Multivitamin powder? If you allow multiple live feeding sessions per day, how many of those feeding sessions do you dust their live insects in this Multivitamin powder?
8.)Do you offer fresh greens and/or vegetables to your beardie's? If so, what greens and/or vegetables do you offer them? Are these greens and/or vegetables fresh, frozen, or canned?
9.)How many days per week do you offer your beardie's greens and/or vegetables?
10.)What time of day do you put the greens and/or veggies inside their enclosures? Do you offer the greens and/or veggies before or after they eat their live insects? How long do you allow these greens and/or veggies to remain in their enclosures before removing them/providing new?
11.)Do you sprinkle the above listed calcium powder and/or Multivitamin powder on their greens and/or veggies?
12.)Do you ever offer your beardies fruit? If so, list all fruits you feed them, starting with the fruits you feed most often in descending order.
13.)How many times per week do you offer the above listed fruits? Do you sprinkle the above listed calcium powder and/or Multivitamin powder on the fruit you offer?
14.)Do you offer any commercially available foods to your beardies (pellets, Beardies Bites, Omnivore Mix, etc.)? If so, how many times per week do you offer these foods? How much of these foods do you feed them each time you offer them? Do you modify these foods in any way (soaking them in something, heating them up, mixing them with anything else, etc.)?
HEALTH HISTORY:
1.)Has your beardie ever been to a veterinarian? If so, is this veterinarian a general veterinarian, an "exotics" veterinarian, or a Certified Reptile/Herp veterinarian?
2.)Does your beardie get either a bi-yearly or yearly wellness checkup with the above listed vet?
3.)Has your beardie ever had any medical testing done? If so, please list what tests he has had done (Fecal testing, Blood Work, X-Rays, Cultures, Bone Density Testing, MRI, CT Scan (CAT Scan), Ultrasound, etc.)?
4.)Has your beardie ever been diagnosed by a veterinarian as having any illnesses or diseases (parasites, bacterial infections, fungal infections, viral infections, Metabolic Bone Disease, Cysts, Abscesses, Tumors, etc.)?
5.)Has you beardie ever been put on any medications or supplements by a veterinarian? If so, please list each medication and/or supplement and how long they were on each treatment?
6.)Has your beardie ever had any medical procedures done by a veterinarian (surgeries, enemas, amputations, growth removals, etc.)?
7.)How often does your beardie have a bowel movement? When is the last time he had a bowel movement? Are they currently normal, firm, formed bowel movements? Are they currently at all runny? Do they currently smell unusually badly? Are his urates currently bright white and moist, or are they dry and at all colored?
8.)Has your beardie ever been impacted enough that you had to give them a special diet or medication to relieve it?
9.)Do you
bathe your beardie? If so, how many times per week do you
bathe him, and for how long? Do they enjoy
bathing?
10.)How many hours per day does your beardie get outside of their enclosure? Are they supervised whenever they are outside of their enclosure?
11.)Do you have any other pets in your home? If so, ease list each type of pet. Do these other pets have access to your beardie? Do they ever interact with each other? How do they get along, if they are allowed to interact with each other?