My understanding is an inheritance is not considered something to be divided. If it is your inheritance, then you should ask for it in full. It is not hers in any context.
I think it varies by state. Where I am, if it is deposited into a joint account, or used to buy marital assets (such as a house, car, etc), them it becomes marital and would be split in a divorce.
But just because her name is on an account doesn't make it any less your money.
