from what you are saying she bites mostly when she is in her cage and you are trying to get her out? If that is the case try using something to get her out the cage like a ladle or even tempt her into a toilet tube or ball. It could just be cage aggression, as hamsters are territorial, and she may behave herself if you just remove the stage of taking her out the cage with your hands
All I can really suggest other than that is patience. If you are letting her run from one hand to the other and she bites you, do you put her straight back in the cage? If you do, then she may have associated biting with going home and getting her way. I had a moody Campbell's like that. Unfortunately, all you can do is put up with a few bites in order to make them realise that if they bite they don't get to go home.
Routine can help as well. If they know there is a certain time for handling, or if they get a treat afterwards, then she might calm down. We generally treat our hamsters with ball time if they are good (and usually give in and let them anyways, but they are so cute and adorable
) and they have all stopped biting us now (except for the occasional Campbell's... they gang up on me in the cage
it's like feeding furry piranhas at times, especially when 2 hide and one looks cute. Reach in and 2 appear from nowhere to take a bite of juicy hand) Make sure when you go to handle her that she has been awake for a while, again they can be grumpy when dozy, and that you don't smell of food. I know you said that you wash your hands carefully, but some soap smells can smell like food, fruit soaps are obvious but I have a violet one that they have taken a shine to as well.
I hope this has helped a bit. On the whole you are doing the right thing, just keep at it and you will make progress