Is this normal?!?!?!

My 3 kittens suckled on my BOY siamese....until they were about 6 months...he loved it, apparently! However, he doesn't produce milk, so there was no worry about them sucking out the colustrum that newborns need.

I would do some research. Do you know if your momma is producing milk or are they just using her as a pacifier?

I think they are just using her as a pacifier, she doesn't mind it too much. Recently one of the cats thats older than her began getting really cozy with her, and apparently she is doing it too. She is just a small calico female, but shes older than the soon to be mom. Weird.

I'd try to stop them. Maybe put a sock around her belly to keep them from getting to her. You wouldn't want them taking the colostrum, and once the kittens are born you definitely do not want them stealing the food and starving the babies!