I know you asked this years ago, but I figured I'd give my thoughts and experiences anyways lol. One kitten in a litter is perfectly fine and normal. My cat Star was a singleton (my previous cat, her momma Autumn, only had Star). Star also eventually got pregnant and only had 1 kitten too. Star...
My indoor cat Star wears a collar and id tag, but only because she has the tendency of slipping outside through vents, open doors, and other regions (our area is too dangerous for her to be outside. No one ties up their dogs or anything, so she could be hurt or even killed by a passing dog). And...