We know that Sir John and Lady Middleton have four children, including John, William and Annamaria, who is three years old, and that they are the center of their mother’s life. We also know that William Middleton is around the same age as Harry Dashwood.
At one point, Lady Middleton brings her “eldest child” to Barton cottage and he is described as being “a fine little boy about six years old,” who became the center of conversation as the ladies “had to enquire his name and age, admire his beauty, and ask him questions which his mother answered for him, while he hung about her and held down his head, to the great surprise of her ladyship, who wondered at his being so shy before company, as he could make noise enough at home.”
Based on this information, we can conclude that John Middleton is likely the eldest boy at 6, William is likely 4 or 5, Annamaria is 3 and their fourth sibling is still an infant.
As we are told that Lady Middleton occasionally apologizes for her “troublesome boys,” we are led to believe the children are rather ill-behaved. While entertaining at Barton, we are told Lady Middleton “seemed to be roused to enjoyment only by the entrance of her four noisy children after dinner, who pulled her about, tore her clothes, and put an end to every kind of discourse except what related to themselves.”
