My Little Singer?

So most people know I love to sing and play my guitar...although I may not be the best in the world, I do enjoy trying. I have written a few songs and the one I wrote for Chris is my favorite one to sing.  Chris loves to chime in and it is my old standby for the time being.  A couple nights ago, we were in the guest bedroom and Chris was holding Tia up on the bed, so I grabbed the guitar and started to sing.  Tia started to gently dance and then all of a sudden she made this horrible face.  Her eyes went squinty, her forehead got all wrinkly, her lips became circle like almost pointing down and she started to make this low sound almost like she was in pain. But she kept doing it and she was still gently dancing. At first, I thought, wow, she's one and already is a critic of my singing...but what we soon found out was that she was singing.  She just looked so sweet and she was just a howling away.  The next morning, we were driving to school and I was signing to some song on the radio and I looked over and saw her in the back seat with the same scrunched up, painful looking face, making a deep howl. She was really getting into it too.  This morning, I just said the word sing and she started howling. I'm telling you, I had to warn the teachers that she is not in pain if she makes that sort of face or sound, she's just singing a long! lol