This is Marcy the hamster, special news!

[Chilli]

Glad to hear she is fine with her stub. =)
My friend and I were talking about dwarf hamsters when I still had mine, and she stated that she once had two females housed together, and one chewed off the others toes on one foot. If Marcy was housed with others in the petstore (like all are), then it might have happened then, though it doesn't always happen.
Just a possibility.

[Christmas_Hamster]

Thats why it is so important to make sure you have suitable cageing^

As long as your hamster si fine then you should not worry.