Cat I found/adopted is possibly pregnant. What do I do?

So I recently took in a stray (likely dropoff) female cat a week ago. She's friendly, sweet, and affectionate. I live in a rural area so it's unlikely she's a runaway. Many people drop off animals in this area. She's maybe 2-3 years old. Haven't taken her to the vet yet, that's obviously the next course of action. Definitely going to spay her after this, if she isn't already spayed.

Anyway, her stomach is large and firm, which leads one to believe she's either pregnant or has worms. She's been in the wild for at least two weeks and was famished when I found her, so it's unlikely that weight is from eating too much at her previous home. Her nipples are long and a faint pink. My bet is on her being pregnant.

If she is indeed pregnant, what the hell do I do with the kittens after she's given birth? I can't adopt any of them. I live with my mom and she has a severe cat phobia. This cat lives in the connecting house to ours, where my uncle lives. I gave the cat to my uncle but go there often to play with her, as I cannot keep her in my house with my mom. He has cancer and can't handle more than one cat. Don't know anyone who'd be able to take kittens in. The animal lovers I know are already drowning in dropoff cats or have cat allergies. The local shelter is almost always at full capacity. How many kittens do cats typically have in a litter? Is there such a thing as a professional cat abortion? How does one take good care of a cat while she's pregnant?

Gonna give her a dewormer soon to rule out worms for certain. Other than her stomach, she seems to be in good health. No vomiting or diarrhea I'm aware of. Gets along well with the dogs.