Advice please! Is it time to induce?

I foster cats for my local shelter. I've fostered lots of mama cats and kittens, and have had several pregnant cats give birth here at my house with no complications. Almost 2 weeks ago (it will be 2 weeks tomorrow, on Friday) I brought home a new cat. When I went to pick her up, I thought she looked VERY pregnant and I expected her to deliver sometime that weekend. She is a very tiny cat, I would guess maybe 5 lbs non-pregnant. She seems young, I would guess a year or younger. I know cats rarely have problems with delivering, and maybe I'm being paranoid. However, two weeks have gone by and I am on pins and needles. She has had milk for at least 9 days now. Three days ago (almost exactly, its been about 72 hours), she had what I assumed to be "bloody show". She has some bloody mucusy discharge. It wasn't very much, didn't smell funny, and only lasted a few hours. I figured we'd have kittens very soon! Now three days have gone by with no further signs. She is all belly- it looks like she has a cantelope in there. She is still eating very well (1.5-2 cans of good quality wet food a day), and she doesn't seem restless or anxious at all. That being said, she is not active and seems somewhat uncomfortable. She mostly just lays in her nest and will purr and want belly rubs when I sit with her. The kittens are very active, I can feel them and see them move clearly. Should I be worried? Is this normal?

Last night Tess finally delivered her kittens. She had 5, but 3 weren't alive. The two survivors are doing very well- active, nursing and full-sized! Very cute little tabbies with white feet. Tess herself seems to be doing very well, and quite relieved. I feel badly for the 3 that didn't make it, but I know this happens pretty frequently with young/tiny cats. At least now mama can move around more comfortably and get into the routine of taking care of kittens!