Welcome to the forum, I'm sorry your dragon is having some issues. Yes, please post photos of both her and her entire set-up, lighting, etc.
It's true that as they get older they tend to poop less and less often, much less often than when they were babies, and yes, 10 days is about the time that I get suspicious, but honestly my male, who lived to be almost 13, would sometimes go almost 2 weeks between poops, on the same diet, lighting, etc. So I wouldn't be worried about 4 days or even 10, unless she has other issues going on. Your dragon is right in the age range when they start to change their habits, they all seem to slow down a bit and become a bit more lazy, start eating less bugs and more greens/veggies, and start pooping less, and it's not uncommon for owners to worry when their dragons hit the 6 month to 12 month old period.
What is her daily diet? Remember that dragons get most, if not all of their
hydration from their live insects and their fresh greens/veggies, so it's always possible that she needs to get a bit more
hydration into her. Does she eat any commercial foods, like pellets or freeze-dried or already dead insects? That can certainly and will cause impaction, especially the freeze-dried crickets that come in the pellet mixes. It's best to stick to live, gut-loaded insects and fresh greens/veggies only.
Gut-loading all of her live insects with the same healthy, fresh greens/veggies that you feed her, right before she eats the bugs, is a great way to get some extra
hydration in her.
Do you feed her any hard-shelled bugs, like mealworms or superworms? In my opinion mealworms are worthless as far as a source of nutrition for bearded dragons, they are mostly fat, contain little protein or other nutritional value to them, and have a very hard, chitlin shell that dragons always have trouble digesting. So if she's eating any mealworms I'd stop them and go to a better choice of live insect. Some people feed their dragons mealworms as an occasional treat, but there are much better choices that contain much more
hydration (remember, they get most if not all of their
hydration from food and not standing water), like wax worms, butterworms, and hornworms, all of which are great live treat insects and contain ample
hydration, as long as they are only fed occasionally in small quantities they are a much better choice for a treat insect. Just my opinion. And Superworms are a good "supplement" insect, meaning a good insect to feed in small quantities along with her main staple insect, to add some variety and give a little bit of a protein and fat bump to a thin dragon, as long as you only feed 1-2 a day at most they can be a good additional feeder. In large quantities they contain a lot of fat and again, a very hard shell that can cause impaction. Not nearly as bad as the mealworms are though...
Also, what substrate do you have in the bottom of her tank? If it's a loose substrate, whether it's a type of sand, crushed walnut shells, wood chips, bark, rodent bedding, seed, etc. this always seems to be a factor in impactions as well, and is just risky and unnecessary, so if you're using any type of loose substrate I suggest dumping it all out, completely disinfecting her tank and everything in it (loose substrates also harbor bacteria, fungi, parasites, etc. and become a constant breeding ground for constant infections, specifically upper respiratory and skin infections, another reason not to use them), and then going to a solid substrate, you can use just paper towels or newspaper until you choose a permanent substrate like tile or non-adhesive shelf liner.
I'd also check all 3 of the temperature zones inside her tank using either a Digital Probe Thermometer or an Infrared Temperature Gun only (no stick-on thermometers, you can't check a Basking Spot Temp with a stick-on thermometer at all, and they are also extremely inaccurate, often off by 10-20 degrees to the low side). Temps that are too low, specifically the Basking Spot Surface Temp (should be between 105-110 degrees F max) will cause problems with proper digestion of their food, thus causing impactions. So double check all 3 temp zones properly.
Also, what
UVB light do you have for her, how old is it, and is it obstructed by a mesh lid? Improper
UVB light for less than at least 13-14 hours every day can also cause problems with the digestion of food and proper breakdown, metabolism, and excretion of waste.