Aw, Bitter, you ole softie! Props to you for saving the poor little thing. Although, haha, given how that the little guy/girl climbed up your leg - you really had no choice at all, did you?
Have you figured out if it's male or female yet? I assume female based on her colouring. Poor little thing looks either very young or very starved. Or both. Definitely needs some TLC.
Yep, a short tail is normal when they are very young.
Oh ETA a warning - if she has been starved, be prepared for some really stinky poo when her system kicks back into gear......we've been there, done that. It's not fun, but does pass (ha pun intended) after a while.