I was struck in that section of chapter 7 by the evolution of Mary's terms for little Charles. First he was "this poor sick child", on her first understanding that she & Anne are to be left alone with him, then he becomes "his poor little boy" (not hers). Her next reference is to "my child" but only as a response to Anne's gentle reproach & it sounds very abstract, & by the end of the sentence she's back to "a poor child" "when IT is ill". When Mary starts considering escape from caring for little Charles, he graduates to "he" & then "little Charles". Once she has made herself comfortable with Anne's assurances that she would not mind staying, he remains "little Charles" & once she is quite convinced that the evening out is in store, he becomes "my dear child". I don't want to read too much into these pronouns & terms of endearment but I don't think it is quite accidental that when maternal duty involves sacrificing enjoyment, the child becomes ojectified & contracted into an "it", only to be resurrected once it is no longer in the way.