New and have questions about my beardie's behavior

[MatikasMommy]

Hi. We have a bearded dragon named Matika. We got her from my stepson about 6 months ago and he said she was a female. Not 100% sure if she is or not. She had been doing really well until a week or so ago. She has completely stopped eating her crickets and will nibble on her greens occassionally. She is also "banging" on the sides of her cage (which are glass) with her face. She's also digging alot. I'm finding her sleeping standing up leaning against the glass. Not sure what's wrong with her. It's almost like she's trying to dig her way out of her cage. I have also seen her bobbing her head. I've wondered if she see's her reflection in the glass and thinks it's another beardie.
If anyhow can help me I'd greately appreciate it. I'm unsure of her age...probably a year and a half old(?).
Thanks