Teddy Cookies
I have a feeling he knows who she is but she doesn't remember maybe because they were either were drugged or drunk and the step sister pushed her in the room when he was alone. He had private investigators looking for her which they found out her name and that she was pregnant. He had a plan and it worked really well. He found her to ask her parents for marriage for his grandfather but it was actually for him which grandpa was the ruse.