When I stopped to use the restroom in a turnpike stop in PA, I didn't notice a sign on the first stall I went to, but inside there was a big toilet and a little toilet, side by side. I wasn't sure what it was, but I knew it wasn't for me, so I closed the door and then noticed the sign which read "Mommy and Me."
I went to the stall next door, but then heard a mother and little girl in the Mommy and Me stall. The mother said something like we each have our own toilet, and the little girl said in the most exhuberant voice, so sincere, "Oh Mommy, this is so cool!"
A few seconds later and the little girl was finished and I guess exploring the stall and found that little shelf that pulls down for your purse, and she said, "What's this for? [and then answered her own question] Oh that's if you want to eat lunch here. Can we eat our lunch here?"
It was so sweet, really. I have noticed in my travels what's now called "family bathrooms" which really does make sense. This was my first "Mommy and me" bathroom.