Python's a great first language, and is always the front runner in conversations I've been part of on the subject "what programming language should X learn first" - it has lots of powerful libraries but very little in the way of stuff you have to do to get anything to work. However, there are lots of other good choices too (some of them specifically for children - Scratch is good, for example, and my DS loves TurteArt which is a language for making a "turtle" go where you want and draw patterns on the way - there are several languages like that). In the end, it doesn't really very much matter - if someone has a reason for finding it convenient or exciting to try some language, it's better to start programming in that than to hold out for the perfect language. I would expect an AOPS Python course to be interesting!
