New lens for my birthday!

Seth took Leif and me to breakfast to celebrate my birthday (coming up later this week) and to bid farewell to Bella and her mama as they head south for a couple of weeks with Bella's other grandparents.

Seth and family bought me a new 50mm fixed lens for my camera, and I couldn't wait to try it out on my favorite model. I see that it's going to take me a while to learn it: the eyelashes on my right were in focus but the ones on my left were not, and the whole image is a bit soft. I guess I'll have to back up a bit more. I've been using nothing but the 35mm for the past three years and three months, so I could use a few tips. If there are any among you who have a choice of a 35mm or a 50mm, I'd love to hear how you choose which one to use.