Need advice on fostering feral kitten

We currently have a feral kitten (female, approximately 3 months old, not yet spayed) in our main foster home, who was trapped about three weeks ago.
She's surprisingly tame for a feral. Although she hisses and growls when someone initially approaches and opens her kennel, she does allow us to pet her and will eventually start purring. She has never attempted to scratch or bite. I've been holding her wrapped in a towel whenever I visit and today was able to pick her up without it and she laid peacefully in my arms.
She's made a lot of progress, but the foster home she's in is very busy right now and she's not getting consistent attention every day. I'm considering fostering her, but would only be able to keep her for three weeks at the most.I have a spare room which I used to foster briefly before and could keep her separated from my three cats. I'd have time to spend with her every day, but am wondering whether this would be a good situation for her or just cause her more stress with the move. There's no real rush to socialize her at this point, since adoptions have been slow. Any advice would be appreciated.
Thanks.

My cat when she was feral absolutely LOVED the furry mouse toys to play with, they kept her very busy. At first she hissed when I tried to play with her with a shoelace, but soon she loved to play with a thick shoelace too. Because I exposed her to toys when she was still feral she is now a loving house cat that loves to play with shoelace and furry toy mice.