My Ziggy cat was also, I am sure, I former "outside" cat before we adopted him. From the minute the windows open in the spring until they close in the fall he would rather be outside. At the first snow I let him out for a second...he freezes his paws and doesn't try to get out for the rest of winter
We have had him almost three years now...he still sits at the front glass door and meows to get out once in a while. He is allowed out in the back on a leash when I am outside. That seems to be a good compromise for him.
Just wait and see once she is spayed and the cold weather arrives weather she still wants to be outside. Even the ferals int he neighborhood don't want to be outside cats once winter comes.
Thanks so much for taking her in and letting her have her sweet kittens in such a safe place.
Good luck and let us know how it goes!!!!