Personality change ?

[Russian_dwarf]

Hey guys so I've kind of hit a dead end with my little girl Echo. I've owned Echo since the beginning of April this year (2015) and she was so so sweet. About three months ago she started getting very nippy, and two months ago she bit me. I was shocked at first, and thought maybe it was something I did. But now, two months later, she's bit me 4 (?) times, each time drawing blood. She's become very violent towards me, I can barely feed her because she won't allow me to put my hands in her cage. I've been trying to work with her, hand feeding, petting, taking her out of her territory to try and touch her, and things were starting to get better until she completely turned on me again. I don't really know what to do anymore. I know that I'm not scaring her or coming across as a threat, because she will climb on my hands sit there, and all of a sudden she lashes out at me. If anyone has any suggestions as to what I can do I'd really appreciate it I hate leaving her locked up in her cage 24/7

[cypher]

This kind of change in is most usually due to either some form of stress in the hams environment, any changes of room, cage, other animals, unusual noise or disruption or it may be that she's unwell, they can be really good at hiding the signs of illness but sudden biting or aggressive behaviour can indicate that they are in pain or unwell.
Is she eating & drinking normal amounts, any weight change, behaving normally in her cage when she's alone, running in her wheel?
It does sound as though you're doing your best for her & giving her every chance to interact with her so I do hope you can figure out what might be bothering her somehow.
Does she have a play pen or safe play area out of the cage where she can have some play time & you can observe her without interacting & triggering the biting behaviour? That would give her a break from being in the cage all the time & you a better opportunity to watch her for signs that anything might be wrong.