Like father like son like mom

I would ask a simple question: did Frank ever wonder if Bobby somehow looks like him, and he ever cast a doubt over this ? What about Marjorie, despite Esther did shed the light before Marjorie left for good ? What about Ada, since they were together for a trip to the hot spring park. I mean, can't Marjorie tell both Frank and Esther were close, and wondered about that ? ( Frank only told Esther about his family tragedy during the Japanese occupation, I figured Marjorie had doubt over it).

In the 50's, did not they have the knowledge birth control, Such as condom? Or did Esther wanted it from Frank on purpose?