Rice Cereal & 1st Tooth

I don't know why, but I really did not want to introduce anything other than breast milk until Hayden was 6 months old. But about 3 weeks ago she stopped sleeping through the night as I had previously enjoyed! I thought it was just her gums bothering her due to teething. But I finally started reading in my book Baby Wise and it said that if your baby previously slept through the night and is no longer doing so, it is probably because they are growing and need more food. So I started nursing her an extra time during the day and this still did not work. I did a couple of other things the book recommended and it did not work either, so I started rice cereal and it did seem to help last night. Some of my friends told me how much their baby disliked the cereal at first, so I was prepared for Hayden to reject it. She had some funny faces, but she ate almost 2/3 of what I made for her. She would open her mouth real wide and eat it and then make a funny face. I guess she was ready and I wasn't! She has been really curious about all the food I eat lately and opens her mouth when she see's me open mine to eat. It is pretty cute. I recorded the first cereal experience so Paul could watch it since he was on alert of course. See below.
Also, yesterday I felt her tooth for the first time. She finally got it, so hopefully that combined with eating more will help her sleep good again. I cannot believe my little baby has a tooth. Five months is pretty early for a baby to get teeth, but my mom said I teethed early too.