Is my bearded dragon normal?

I have a 3 month old bearded dragon who is 6 inches long . ive had it for about a month now and it only eats about 10 crickets a day , ive tried to feed it waxworms and small dubia roaches as well and it doesn't seem to like them . my beardie is just awfully skinny but it acts like a normal baby beardie would . I've also tried offering baby food and it likes that but I try to stick to insects. any advice to help me fatten it up? all of the other baby beardies I've been seeing that are about 3 months old are a lot bigger than mine and I'm just concerned. I will be bringing it to the vet when it gets a little bigger.

- tank size 40 gal breeder
- light is a reptisunlight 125 watt with 10.0 uvb
-i give baths every 1-2 days
-basking spot is 105-115
- cool side is 85-90

I'm not sure how to add a picture as I am on a cell phone . thank you!

For your uvb is it the compact and tube light together or just the compact bulb? Usually wrong uvb lighting can lead to MBD, being slightly smaller than normal, not eating and a few other things. I helped someone on a different site that had a compact bulb and their male beardie was 2 years yet was only 12 inches long because of the wrong lighting.
What exactly are you feeding her/him every day, along with whats its substrate/bedding.
3 months from what i hear and guess the normal average would be around her size, maybe 6-9 inches. My juvenile was 10 inches at 4 months and now around 16-17 inches at 8 months.

both of the lights are together I believe the bulb is called a reptisun
the substrate I use is tile
I offer it crickets 3 times a day but with 1 of the feedings I put calcium powder with d3 on them and I also offer it small dubia roaches 2 times a day . fruits and veggies are offered 2 times a week

Can you post a picture of your setup? The lights as well. Are you dusting the food with multivitmins two times a week as well? Also once it reaches around 6-8 months probably offer greens everyday so it'll hopefully be more willing to eat greens most of the time once it reaches 12 months. Also around 12 months you can cut back on the insect feeding to once a day.