awwwww they're so precious!I'd take them off ur hands if it were remotely possible.
You can't separate the mum from the babies until they are at LEAST 6 weeks old. If the mum gets tired and doesn't want to feed, just get an eye dropper (from any pharmacy) and some special cat milk from a pet store (cat's are lactose intolerant & shouldn't drink cows milk) That should keep the little bubbies happy. They can start on solid foods at around 4 weeks...
Just make sure the mum gets plenty of rest & the little babies are kept away from other cats. As for pissing the mummy cat off... I think the kittens are more like to piss her off than you... so don't worry (and no, she will not try to kill her babies).
I hate people who dump animals... they make me sad.
P.S.
The last pic of the kittens down the bottom...
they look Ginger & Tabby....??