Oh, yeah...save your laundry!
I leave some of my unlaundered shirts on the back of the couch for Assumpta when we're gone for the weekend, and the catsitter reports that when he comes in, that's always where she's sleeping.
She may be happier if she has her own bed, toys, bowls, and litterbox with her, if there's a special blanket or pillow that she loves, send that with her.
If your cat's prone to any health issues, you might have a quick vet check before you leave, and you can use that time to make arrangements with the vet for emergency care whie you're gone.
And this probably goes without saying, but make sure that your friend keeps Peaches indoors to prevent her getting lost in a strange neighborhood. Also, make sure she understands any special care or medicnes that the cat needs, how she likes to be patted and played with, stuff like that.
Cats usually don't adjust to new situations very quickly, so see how it goes and take your cues from Peaches. And I am also a huge worrier...but I've learned that just means my mantra should be: "The actuality is never as bad as the anticipation."