OK, been busy and have not read through all theories yet, the more I thought about everything, mulled it over, off and on, I think there's a possibility that Mom knows baby Lisa's Dad is a third party. She's known it all along. Because there is a legal assumption that Mom's husband is the father it has to be rectified before she can marry her fiance. This requires a DNA test or for her boyfriend to testify in open court in front of a judge that he claims to be the father of Lisa. I'm not sure of the legality in their state, it may still require an official DNA test. If she knew that test was coming up, very soon, there's a motive to....stop that test from happening. Her whole world would fall apart IF her husband and fiance were not the biological parent of Lisa. Just a theory, as I said I haven't read through the thread so if someone else thought of this first, I agree.