Re: questions about my cats..
I suppose it would be normal. It seems the 1st cat is showing a strong maternal instinct.
Out on our farm when I was a kid, the female cats usually kittened together in the same large box and both cats worked together raising both litters. The kittens would nurse from whichever mother was there and each mother would care equally for the kittens.
We eventually wound up with 30 cats and my folks did an aggressive spay/neuter to prevent more kittens.
As long as cat #1 can physically care for all of the kittens she 'claims' as hers, I wouldn't worry about it, though I personally think it would be best if both cats could raise them together in the same nest OR you would need to seperate them so they only had access to their own litters. This helps each cat to optimally care for their litters, instead of being unbalanced with their resources, like one cat having 8 kittens to nurse and care for while the other cat only has 3 to nurse and care for. The cat with the largest litter is going to have a more difficult time providing milk for such a large number compared to the cat with the smaller litter.