Hi Christina,
1) Nowadays you can spay your dog before her first heat, it's really up to you. You can ask your vet what he/she thinks it better. What is hard to know is when your baby will go into heat and it's preferable to spay your dog a couple of months after her heat (to avoid extreme bleeding)
2) A dog matures sexually at around 6 months. A 10 week old pup won't be interested in that
