Damn. Congrats to you both for being so hot for each other you’d want to have sex even with her folks just feet away.
But yes, I think if they heard you, it would be awkward as hell, so, if I were you, I’d keep it in my pants. Instead, use the two days as foreplay. Tease each other by talking about what you’ll do once you’re home. Make out, throw in some groping, and think how amazing the sex will be in a few days.
If you really must have sex, do it when there’s no way her parents will know—e.g., they’re out, or it’s very late at night and they’re likely sound asleep. But first make sure the bed doesn’t squeak or bang against the wall—actually, the safest bet may be to throw some blankets on the floor and do it there.