If looks didn't convince you, we have hard evidence that Maisy is a Rutledge.
Maisy and Johnny come from a long line of people able to sit in the most uncomfortable looking squatting position for long periods of time. (It's a really awkward position that I cannot sustain for any length of time. You have to be born with Rutledge blood to be able to do it, marriage doesn't count.)
Whenever Grandpa, Daddy, Johnny, and now Maisy are playing or working on the ground, they squat. (I've heard rumors that great Grandpa Rutledge used to squat while working out in the yard and I'm guessing there were probably a few Rutledge's squatting on the Mayflower.)
Below are examples of various generations doing the Rutledge squat.
Grandpa and Johnny squatting in the yard
Daddy and Johnny squatting on the beach
Maisy squatting with toys
Now, back away from your computer and try it!