Yes, but with Max around, Dina would be in Jonah's life FOREVER. I do not think Rebecca liked Dina just from the things Mary Zahau has said. I bet Rebecca seethed every time Dina and Jonah attended a school function or soccer game for Max. She had to sit home every time Jonah left to do that. And Dina is very attractive as well, and she and Jonah share that beautiful little boy. They would always be his parents, no matter how much Rebecca wanted to be in a mother role. Can't you imagine Rebecca always wondering if Dina would get him back? After all, he loved Dina enough to marry her and have a child with her.
...
And then what? Why would she kill herself just a couple days later, after supposedly getting a phone call that Max's condition worsened? According to you, she would have just accomplished getting Dina out of her life. It doesn't make any sense whatsoever.