I would call them cats now. Some people call them kittens for the first year. Really they're like the equivalent of teenagers so they're kind of in between. They're adolescents.
If you were showing them, you would show in the adult classes. and that probably influences my thinking of them as cats. I think in the GCCF it starts at 9 months. In CFA and TICA it starts at 8 months. and in FIFé it starts at 10 months.
In the different methods of comparing cat age to human age, most seem to agree that by 2 years old they are like a human in their mid 20s. but there is a difference of opinion on what they are at 1 year . In some methods it' s compared to a 15 year old human and in another method , a 1 year old cat is compared to a 20 year old human. I think the latter is more accurate for most cats based on when they usually reach puberty. But for some breeds ( and some random-bred cats) they are later maturing. So far as I know, Egyptian Mau is not a particularly late maturing breed
If you go by them being like 20 at 12 months, that would make them like 18 at 10 months.
if you went by the other method of estimating, that puts them at 15 at 12 months , they would be just around 14 at 9 months.
Domestic shorthairs don't reach adult size until they are about 2 years old. Mine sure haven't looked the same at 2 as they did at 10 months to a year. And I don't just mean in size, they get that mature adult facial and body structure at about 2. Plus they still need more food in that second year than they will past 2 years.