Sure there is some money involved, but would she be happy with uneven
flooring a year from now ? The level compound is only $7 a bag where I
live.


I suspect, given the descriptor "rolling" in the original post, that
the unevenness is a little more than what you'd normally try to
fix with leveling compound.

Depending on what's under the existing surface, sheet vinyl or
even paint is going to be the most cost-effective.