When I was 13 I had to make do with a netbook, trying to shoehorn Windows XP, and later 7 into that 16 GB SSD!
I think something better (cheaper and whatnot) would be an Atom tablet like the ASUS Transformer T100, the Dell Venue 11 Pro (base model) and such.
at the least, I think it'd be better to spring for either the original Surface Pro or the Pro 2.
I might have appreciated it, but I don't think id give 13 year-old me a Surface Pro. (although I probably wouldn't have broken it) I just didn't have a major use case for that relative amount of computing power and cost for school a few years ago.
But eh, depends.