who has rights to a child

if you two are not married, and this is a Wisconsin case,  the mother has sole legal custody and the (asumed) father has no legal rights to the child whatsoever until paternity established. That is done by either a joint voluntary acknowledgment of paternity filed on the proper state forms and properly filed in Madison, or by one of you filng for a formal paterntiy action and requesting DNA testing to establish whether he is or is not the biolgical father of the child. Until that occurs, he has no legal rights to the child whatsoever, and his marrying certianly doesn't not bestow any legal rights on his soon to be new wife. The answer to your question is false. She would have no rights either to the child, other than as to step parent visitaiton rights, should their marriage end, and assumingly he would have been adjudicated to be the father.