Pregnant Foster Cat- Im just a little worried

So I took in pretty miss Molly and she is definitely very pregnant. She went to the vet and was tested for FIV/FeLV and they were both negative so thats great! She is expected to have her kittens in the next week or two. I have only had two other cats pregnant before and they both didn't go as planned. One cat had a miscarriage and the other ran into problems during birth with the first kitten getting stuck in the birth canal (it was too big for her according to the vet) and her having to have an emergency c-section and then her milk never dropped so I bottle fed them. The rest of the rescue kittens I have had have come to me at least a few weeks old. So I am not worried about the kittens when they get here, so much as I am worried that something will go wrong again with the birth. Is there anything in particular to make sure that this time around goes much smoother?

I've only had one cat give birth and the only help I had to offer was to clean the birth sack off of one kitten because the kitten right after it came so quickly. I've heard it's good to have dental floss if she doesn't cut the umbilical cords, and make sure to count the placentas ...that they come out. You know she will eat them, right?

http://www.thecatsite.com/forums/showthread.php?t=74659

Also check out this thread, there are a whole bunch of links, and good luck!