Twins

I've heard about kids looking or acting very similar to siblings. However, I'm slightly convinced I have two of the same kid. There are many times when Todd or I will look at Harper, and it feels like it's 3 years ago all over again... with an additional two toddlers! In many cases, I feel like I'm cheating because I have the answers. No guessing-games with this kid because she's walking the very same footsteps as her sister. Not sure I'm ready for another Em (version 2.0 her Daddy's legs instead of mine so at least she's got that going for her), but here we go again I suppose!

Can you tell which is which?

(Besides the obvious upgrade in photo-taking and camera abilities?)