Her R: ability says I can commit 1 of theres after I play an attack. Does that mean I can play one attack and use it several times until I run out of foundations to commit or can I only use it once per attack I play?

To answer your question once per attack duke ok ?

you can only play an R: on a card once per trigger.

Say you had a foundation with the same ability, and you had 3 of the foundations in play. You could play it once on each foundation for a total of 3 times.

hope that helps