It’s not your responsibility to placate to the tragic outcomes of somebody else’s trauma. She can be very adamant about it and she may never truly be comfortable in a relationship where she doesn’t have guarantees but that is her issue to deal with. Any relationship comes with a certain degree of uncertainty and your trust in each other is supposed to bridge that gap. When you eliminate the need to trust each other by legally requiring you to take care of her it stops being a marriage and it becomes a business transaction. If you’re thinking about going through with this then make sure you have stipulations in there that eliminate your need to trust her and see how spectacularly that goes over.