who is the owner now for this house?

if her's name on the title then You can find how she can change name.Her hu*****and must have notory before he dead. otherwise she was not able to change name.50% of house value belong to first wife.I assume only one kid then the kid has 25% of house the man has 25%+50%=75%. after the man dead then the kid and the second wife share the 75%. the kid can 25%+75%/2=62% of house if the man without will. But if the man left will to second wife then the kid can have 25% and the second wife have 75% of value.