Long term pet sitting; cat is pregnant.

Long story short, I’m pet sitting for someone who wasn’t able to properly care for the animals. I’ve gotten them to a healthy weight. Which is why I didn’t immediately notice the cat’s weight gain. She has a significant belly now, pronounced nipples. I have her secluded in a safe room with two separate queening boxes, food, litter and water. Nipples became protruded on Thursday, she has less interest in food, very snuggly with my partner and rubbing up on my dogs, and her sibling dog.

I was not informed the cat wasn’t fixed until 3 weeks after starting this sit. She was an absolute escape artist during that time. Quite likely it’s my fault she’s in this situation.

I had to bring sibling dog to the vet (unrelated) and they were limited in what they could do, and informed me that they went beyond what they should without owners consent.

What can I/should I do? I am worried that taking kitty to the vet will cause more stress than good. I am well armed and prepared for kittens as I can’t make the spay/abort decision. Owner seems content with the fact that kitty is pregnant. I have friends who work with/have fostered/dealt with pregnant cats and kittens.

At this point, I want a safe arrival for the kittens, a happy and healthy mom, and that I won’t get in trouble for taking kittens to the vet after. I would like to take mom in for an ultrasound and to figure out what’s going on, but once again, I’m worried about stressing mom, and should I lie about the situation? She’s mine and she got out? A stray? I want to be able to make the right and best choice…