Well.... I don't have that much experience with cats interacting but here's my two cents worth:
If you're getting your own room at your friends house, then maybe you can set her up there with her litter, and food etc. And then hopefully you can work out a schedule with your friends cats, so that wendy can come out and smell around a bit and be with you etc. And while wendy is out, maybe your friend will put her cats in a bedroom or a spare room etc.
It really depends on how accomodating your friend is willing to be with you and your cat.
The main thing is that you don't want wendy to be alone right? It'll be a bit easier for you in this situationas your aim is not to make friends out of the cats. So as long as you and your friend take great pains to keep all the cats, out of each others way, i think it'll be okay for two days.
But you might want to make absolutely sure you bring kitty litter. your cats own box. And if you're going to bring new kitty litter, then just bring a little bit of the old stuff too... just to make ABSOLUTELY sure your kitty knows where to go and doesn't go on the bed or anything...
If you're careful enough it should be okay...