I wouldn't wear the heels myself. I would wear dress boots or pumps.
They are called "fuck me shoes" for a reason. The reason is that the large majority of people see them and assume the woman wearing them is looking to get laid.
Doesn't mean she is-but it is the message sent.
Especially it being their home and not wanting to show up the "queen of the castle"- business casual slacks or nice jeans with blouse or sweater, boots or pumps, keep the make-up "office friendly" not club make-up.
Take a bottle of wine or flowers to the "hostess".
"Love As Thou Wilt"