I’m with @Empireapple . This is not the D’s problem to solve and she needs to be firm, but fair. Otherwise it will happen again and again.
I think this “problem” is indicative of so many kids these days. They want to have sex, so the roommate has to leave the room for two whole nights? Let them figure it out the old fashioned way. That’s what janitor closets are for, right?
One night is maybe reasonable to ask, but two? OPs daughter is expected to majorly inconvenience herself so a couple of teens/young adults can have some hanky panky. Sorry, but there are many creative ways for the lovebirds to get their alone time, and it’s more than generous for the OPs D to give them a few hours of privacy over the two days.