pregnant feral cat

I've been taking care of a feral cat and her son.My landlords took their time in signing the form needed by the foundation that would take care of the spay, neuter, and vaccines so before i could get her in she took off and got pregnant. while she was gone i got her son neutered. She just started showing up again but it about 5-6 weeks along i'm guessing. The people that lived her before said she had her first litter behind our garage in a bunch of spare tires. i've put out nesting boxes around the house in quiet spots but i was wondering whether or not they tend to deliver in the same place or not. i want to make sure she's okay after having them b/c she most likely won't have them when i'm around or where i can find them and so that when they are weaned i can get her spayed right away. what is great is that the foundation is going to pay for the spay and neuter of the kittens as well!!
hope you can help me out,
Angela

Chances are strong because she is feral, she will reject any nesting boxes you put out for her. Instead she will find what she deems to be the safest place to have her litter. All you can do at this point is make sure she has plenty of good quality food and water and a place where she can get in out of the elements. Try to feed her the same times every day so she knows she can depend on you, this is the first step to building up her trust. There is a feral colony forum where the people on there are experienced in dealing with this type of situation. I myself, only deal in feral rescues. Good luck Once she starts to trust you, she will bring you her babies on her own.

Thanks a lot. that's was i thought i just wanted to get advice from someone who knows. i feed them every day at the same time on our porch. she trusts me quite a bit i think. she'll roll over and expose her belly for a scratch and rub against me. some days she's a little more timid. She doesn't trust any of my roomates so i have a feeling she won's have them on the porch where i would like her too. there's just too much traffic by people she doesn't know and stuff. I'll keep you updated. Thanks again
Angela