"Mama could hold you."
"Mama could get you some water."
"Mama could read Matilda a book."
Before this development she was constructing her sentences/requests exactly the same, only leaving out the could:
"Mama hold you." (Incidentally I hear this roughly 1,000 a day, it is M's stand-by whine if she is tired/hungry/needing anything.)
"Mama get you some water." (Occasionally with a please thrown in there)
"Mama read Matilda a book."
I love the new addition of "could" to everything because in my head she is just making an assessment of the situation. I imagine what she really means is "If Mama was doing a better job she could _________."