It's hard to say for sure. Ana could be a blend of real experiences and creative imagination. Maybe it takes inspiration from real-life situations but is not a complete account of actual events.
Well, it could strengthen their bond. The idea of having a child together is a huge step, and they might become more united in their goals for the future. For example, they could start planning for the baby's future, like where to raise it and what kind of education it will have.
The core of the Ana Delvey story is factual. But keep in mind that in its portrayal, details might have been tweaked or focused on differently to create a more compelling narrative.
Maybe Saoirse Ronan for Ana. She is a very talented actress who can convey a lot of emotion. And for Christian, Robert Pattinson could be a possibility. He has experience in playing complex and somewhat mysterious characters.
One main challenge was probably her physical health. With such a high weight, she might have had trouble with basic mobility, like walking or getting out of bed.
I'm not sure specifically as I haven't read the full account. But it could be about her personal growth, her experiences in her family, or her own journey in life.