Then, a couple of days ago, I heard Ireland say, "My baby. My baby. I want to hold her!" and it clicked! I knew not only where the mysterious pronoun had come from, but the phrase itself:
We moved to Indy in April of '07-Ireland was about 5 months old. She's now 2. For most of her life, Elieth has run up to her at church shouting "My baby! My baby! Let me hold her!" and then smothering her with hugs and kisses.
It seems to've rubbed off.