My cat had kittens and it took about 2 or 3 months in total as she only had 2 kittens but that is the normal months 2 0r 3 months :)
I had witnessed my best friend's cat give birth at a very young age.When you say ''how long does it take for a cat to give birth'' it really depends on the amount of kittens. My friend's cat had 4 kittens and all together with the birth time and labor time it was about 4 hours maybe.But with just the birth time it was about an hour and a half.But the amount of time for birth and labor is different for every cat, I mean its not like every woman giving birth and in labor takes an hour.Right?
If it has been a long time she might have birth complications so think about calling an animal hospital
It takes about like if your cat had 4 kittens it would take 3 to 4 months or if she has more 5 months