At least it's talking?

Two dialogues, approximately 15 minutes apart:

Dialogue Number One during which she never even looked at me:
Me: Hey, sweetie, how are you doing?
Rachel: (angrily) It's my birthday!
Me: Okay, now you need to put on your shirt, okay?
Rachel: It's not your birthday!
Me: You're right. It's not my birthday. Please put your shirt on.
Rachel: (tearfully) Is too, it's pink! (the shirt is green, but she's not looking at it, so I don't know what she's referring to for sure)
Me: Do you need some help?
Rachel: You're talking like a grandma! It's a spider!
Me: Okay. I'll be back in just a minute. Please get dressed.
Rachel: Don 't bite me!
Me: (after leaving for a minute and coming back) Thank you for putting your shirt on. Now shoes and socks, please.
Rachel: I'm not going.
Me: Sit down so you can put them on.
Rachel: (yelling) It's a birthday cake! It's not your birthday! It's my birthday!
Me: Pull your sock all the way up so it won't hurt your toes.
Rachel: (nearly crying) Is too, it's stupid! It's not pink! You bit me! I'm not a girl! I'm a boy! Rachel's a boy! I'm not going! It's a spider!
Me: Let's hurry and get these on. There, all done!
Rachel: No! It's not your birthday!


Dialogue Number Two, which she initiated (even coming into a different room to find me) and made complete eye contact:
Rachel: (sounding sad, but not angry) My lip hurts.
Me: Here, let me see.
Rachel: (pushing her bottom lip out) It hurts.
Me: Hmmm, I don't see anything wrong. Would you like something on it?
Rachel: Yes.
Me: There. Does that help? Do you want more?
Rachel: (smiling) Yes. (after a little pause) Thank you.
Me: You're welcome. Tell me if it keeps hurting, okay?
Rachel: (leaves to go look at a book).

We definitely have our ups and downs. They used to follow a trend of some sort, getting progressively better or worse over a period of time. Now it seems totally haphazard and I have absolutely no idea what to expect out of her at any given moment. After all that talking, she sat and looked out the window with a book on her lap, and didn't say anything for nearly an hour. She totally ignored everything I said or did. It's a little confusing, to say the least.