>>1 you shouldn't be worried about how a child is being raised unless it's actually serious, the sheltering of children to an extent is normal. Just tell it like it is, scientifically.
Reproduction is completely natural and is how species make "babies", the process of making babies is called sex and that leads to pregnancy. It takes place between a male and a female. But just because sex is natural doesn't mean it's okay to do it all the time, you should wait until you're married.
....this is how I would explain it, feel free to change it a little, I hope that it helps. And it's not so awkward if you really think about it :3