Yes it's Sativa. This particular strain has been around for 75years and this plant is from the same line as the original. I was really lucky to get this clone from one of my clone bars here in Denver.
Looks healthy. Unless you have already ran her, sounds like you haven't. You just never know what will turn out. Seen snowstorm at 3 weeks, but turned out "ok". But your in good position health wise to find out