My wife died recently and her daughter (my stepdaughter) and I have been comforting each other on our mutual loss. She looks just like her mother and I have fallen in love with her.
Queenie, would it be wrong for us to get married?—Lonely widower
You are not related by blood so legally there is no impediment. However, you are both still in mourning and what you feel for each other may be only temporary. That is, assuming she shares your feelings at all – she may think of you as a father figure rather than a potential mate.
Give yourself, and her, plenty of time to get over your loss and figure out what it is you feel for each other. And try not to be too disappointed if it turns out not to be the marrying kind of love.