Based on the text of Chapter 21 of the book, does life change at Penny's house after Mr. Mulligan marries her mother and moves in?

Based on the text of Chapter 21 of the book, after Mr. Mulligan marries her mother and moves in, life at Penny's house changes for the better because Mr. Mulligan he is able to to deal with Pop-pop; and that is something for which Penny, her mother, and Me-me are grateful.