What defines OCD?

I wanted to add a few of Abby's funny moments. Whereas Isabel is bipolar, I think Abby is a bit OCD (unless it comes to her room). She loves to help me clean up, again, with the one exception of cleaning her own room by herself. When it comes to making my bed, cleaning the kitchen, she loves to do it. I noticed it would take her awhile to pick up the diapers, and put them back in the cabinet, and wondered what she was doing. Come to find out, that just putting them away was not good enough for her. When I looked at the diapers, they were all in separate piles. One Elmo pile, one Big Bird pile, Zoe pile and so on. This is how she likes to clean up. Also, in that same weekend, I took her shopping. She had to "fix" all of the clothes and shoe racks as we passed. They all had to be even. If some of the shirts stuck out a little further, she had to fix it by pushing it back, or even moving them to a rack that was less full. We couldn't move on until she had done this.
Abby has also been preparing for Kindergarten, and I think she has been doing pretty well, but after a phone call from Tia (doing a project for her Early Ed. Class) I realized that I hadn't been working with opposites with Abby. So this morning I asked her a couple of opposites questions. My last one was "If you aren't sleeping you are?" And what did she respond? "In trouble". So true! But it wasn't exactly what I was looking for.
Last I have one of my favorite recent pictures that she drew for me. I was going to ask when I need to discuss "appropriate", but I think it is more my mind that needs to get the "appropriatness" adjustment. So, if you are having problems like me, it is an elephant....and a lion. Anyway, for those of you that don't know Abby, you should. She is a whole lot of fun!