Looks great!
its tail is alright. Itd be good to get it a little fatter, but shes in no danger right now.
As for size, she looks to be a mid-juvie. Id say about 5-6 months old. She will get bigger! lol. She looks to be between 5 and 6 inches, and they typically get about 8-11 inches, but she wont be a huge monster or anything! no worries. lol
At her size id say she should be eating maybe aout 5-9 crickets a night (some are piggies though!) and should have the mealworm dish with her at all times.
To help her adjust to you handling her, and to help fatten her up: give her a waxworm once a week/every 5 days. Once she settles in you should begin the "taming" process by letting her get used to your hand near her in her tank for a few minutes each day, and then touching her, and then gently handling her everyother day and then everyday. At this time you can give her the waxworms as treats about once a week when you take her out for her daily handling.
Good luck!