Stray/Feral cat, probably pregnant....

I know cats can get pregnant shortly after having kittens, but how pregnant is she? (I will post pictures later, camera is dead! D: )

We are fostering her and her kitten, they are malnourished. The momma cat has all of 3 teeth. The baby although she is probably over 8 weeks old, is about 1/4 - 1/3 the size of our cat of a similar age. The baby is wormy, it is hard to tell how wormy the momma is because she is fat, like pregnant fat! They are being wormed by Panacur, well the momma is the babies wormer might be different. 

Obviously she can birth kittens by herself with only three teeth. But is there anything I should worry about? 

The stray/feral status of this cat. Well she seems to have been someones pet at some point. She doesn't hiss or growl at us, but the kitten, every time you go near her she hisses, It is actually kind of cute. Because all she does is hiss, no growling or trying to bite. 

It is going to be very hard to tell from photos how pregnant she is especially since they have worms which can make them have a big belly.

With her and her current kitten already being malnourished, another pregnancy and nursing another litter is very hard on her. and the fetuses sure would not have had the best start in life with the mom having had back to back pregnancies and is malnourished and full of parasites. So they might not make it anyway or might be very small and weak.
Also if she got pregnant so quick without her uterus having a chance to rest, that increases the risk of uterine inertia. that she could have trouble having the next kittens.

I think you need to at least consider spay/ abort . but I would take her to a vet, and get as much info as you can to make a choice . I just think you need to put the mama first. because it is not even known if another litter would live.
Poor mom with so few teeth makes me wonder how old she is and how many pregnancies she has had already. I am glad she finally ended up in rescue.

If you decide to go ahead and have her have the kittens, her having only 3 teeth make me concerned about dental disease / bacteria that may be transfered when she chews off the umbilical cord.
It could also make her not want to do that if she has mouth pain.
It is normally better in every way to let the mama cat do as much as she can/ will as far as the birth and taking care of the newborns. but some people would say that in this case you should pinch off the cord yourself with clean fingernails (or tie it and cut it with sterilized scissors) .

I think it depends on how the mom reacts. She may not want you to interfere. but if she does it herself, I would be extra careful to put some antiseptic on that umbilical stump afterward and for at least the first several days as it heals.