Just because the other one isn’t crowing doesn’t mean it’s female as they might not mature at the same rate. And coturnix males will rape anything in sight, of either sex. Crowing is what the males do, just as with cockerels.
Unfortunately it can injure the bird being mated because the male clings on with his beak when mounting the other one. The female then tries to shake him off (the males just get in with it they don’t woo the females beforehand and get consent) he hangs on strongly, then falls off to one side, still attached by his beak to the feathers and skin of the hen, and in the process she can get chunks of hair and skin pulled out on her shoulders and head before he detaches. With my first lot I kept coming down to find that the cage was covered in blood and one of the girls was injured. One had to be put down as her eye had been pulled out.
In the end I had hatched 6 females and 13 or 14 males from two incubations. This imbalance of the sexes is common with quails, judging by what I’ve read and my own experience. I separated the males as soon as I knew their sex for sure, but they seemed to get their teenage hormones overnight so it was difficult to separate them before they had got to the girls. So I culled all the males, and the six females lived happy, peaceful and productive lives for several years together.
My advice would be to have a spare hospital cage set up in case this happens, and also get some antiseptic spray suitable for birds in stock, which you could apply on a cotton bud to avoid spraying it the bird’s eyes. I used a second hand hamster cage price £2.50 from the recycling centre shop. Just in case there is trouble ahead ....
From what I’ve read on here from other keepers, this applies more to coturnix quails than to Chinese Painted, which are smaller and apparently live happily in small domestic families of one male and up to 3-4 females. They also go broody and sometimes hatch chicks naturally, with the male taking a protective interest. So maybe they are better if people want quails as pets, although if course the eggs are tiny and not so useful in that way.