Don't mean to sound rude or anything, but you might want to work on the "spay fund" as much as possible. If she's been "hanging with a friend" it might already be too late and trust me, proper care, feeding and re-homing of a litter of kittens is going to cost more than a spay would. Check around with local shelters and vets because there may be some low-cost spays available to you. I know here in the city of Chicago, if you live in a certain zip code area, spay and neuters are free. All you have to do is get the animal to their clinic on a certain day. But free is definitely worth looking into.

I think you will have no problem getting her in. She may still want to go out, and may become a "door darter" meaning she will dash out the door the second it's open, before you even have a chance to think that she might be there, so spaying her is the best route to take.