well my kittens were born i touched them the same day they were born, and nearly everyday since. It can depend on the mother cat, my cat is very trustworthy of me, we are very close, she is my shadow. the best thing to do to start off with (i think) would be to sit in the room with her and the babie and stroke them to start with, see how she reacts and then slowly work toward picking them up.

 

Like Zalensia said it depends on the mother. I wouldn't suggest rush things and handling then too much. If you do want to touch them, take it slowly. First start by just sitting in the room watching them and maybe petting the mother that way the she'll knows you're not going to harm her babies.