I agree with all current replies. It sounds like your cham is a female, if she is digging. Could you perhaps upload those pictures again or send us a link to where we can view them?
Maybe try something very enticing, like a basic little wriggly hornworm. They are mostly water, so they won't be too hard on their digestion. Make sure if you do go this route to feed her small ones or ones with the mandibles cut off (you can just use nail clippers or something), because you...
I agree entirely. I was just thinking that when she is outside, it is hard to keep her from eating things that fly and land around her. I mean, I don't encourage it on a daily basis or anything, I was just seeing if she would be okay if she did happen to eat one or two.