Bearded dragon behavior weird...?

Hello my names Isaac and i have a beardy called Esther. I'm a new bearded dragon owner and was given Esther who is 2 years old about 2 weeks ago. Before Esther would allow me to pick her up fine and would not show any aggression towards me. Now she will always when i put my hand near go and open her mouth to look like she is going to bite. She is also constantly digging now everywhere.

I looked only and have made 2 theories to what may be the problem. A lot of her behavior looks like she could be about to lay a clutch of infertile eggs, so i put her in a box with wet sand for her to dig in, unfortunately i left her in for about 2 hours and she stayed in one spot and did nothing. My second theory is that her old owner used to feed her locust where as i started to feed her super worms, and i was thinking maybe she thinks my fingers are also supper worms? It sounds kind of stupid when i say it but i really don't know what the problem is, so it would be very nice if someone could help!

Both of your theories are plausible. I would keep offering time in the dig box and see if she responds. You could also try some fleece scraps in the tank for her to dig around in. perhaps she just wants to burrow to feel more secure. The change in diet and location may be hitting her and have her off a bit as well. It's hard to say for sure. Has she stopped eating or is she still going for the bugs when you offer them? If she is developing eggs, it's important to try and get her calcium rich food and keep her hydrated.

At 2 years old I suggest worms as a treat but she should be getting a nice big salad every day with a variety and rotation of ingredients as her staple diet. If she isn't used to that it may take some time to get her onto veges but it's an important change.

I kept her diet that her other owner did which was bugs one day then veg the next. I calcium supplement both the bugs and the veg. The theory about my fingers being worms i think i may have debunked as when i put on gloves (which are black and totally aren't the same color as the worms) she still faces her head towards my hands and when i pick her up she closes her eyes like she is irritated and her beard goes black. Before when i was picker her up within the first few week of having her, she was perfectly fine. Its just this past 3 days or so where she has been digging frantically and seems more aggressive towards me, and in no way have i been rough with her or neglected her, i have been nothing but gentle.

Update : She has not laid any infertile eggs and i have changed her diet back to crickets. Unfortunately there is not sign of a change in behavior. Her beard is almost constantly a very dark black and she never wants me to pick her up or anything.

Any comments and help would be much appreciated.

If her beard is still dark black you may want to bring her to a vet for a checkup. A blood test would help reveal issues with her organs and an x-ray might show internal injury that may be causing her discomfort. It's possible she's hiding an illness but it's hard to say without further information.