YES to the vet. If she has a fever especially — she probably has mastitis.
If no fever, she is probably jsut engorged. I don’t suppose you could try to “milk” her or even put warm washcloths on her teats and help her release some milk, enough for the kittens to get ahold?
We just got a kitten yesterday — who woke us all up at 6 am wanting to play - ugh - but sooo cute.
Good luck. I know EXACTLY how that Mama Cat feels. BTDT. Well, not the abandoning my kittens part. LOL.
She doesn’t have a fever. I’ve been watching carefully for that, which would qualify as an instant “NO_BRAINER” decision to go to the emergency vet :-)