Sults has given you some great advice! I want to compliment and encourage you!
This is a really emotional piece that any parent would feel deeply about! As for the 'alien' thing, a newborn is a kind of alien creature! Muscles and control need to develope, and they are trying out new experiences all the time. The feeling of 'another hand' is foreign to them, too! It's an exciting time!
If you're worried at all, I would simply recheck your proportions and relative 'landmarks'. I think you may be questioning the third toe in particular. However, keep in mind the activity this piece depicts as the little one explores the world around their foot!
This is an exciting piece! best wishes!