That's how you know she really cares and is a keeper.
Ok careful here, this happened to my uncle, his ex wife helped to pay for a small part of his house's mortgage (he took a loan to pay for a master's degree on accounting as a civil servant), and after the divorce she used that as an excuse to demand half of the property's value, making bank out of it
It also turns out she was cheating on him with some dude she met decades ago
The moral here is that, sometimes what looks like a keeper is actually a schemer, and to always sing a prenup