I really see no harm in Lady Middleton.

The only subject she has something to say on is her children.
Her only interests are her home and children.

My older daughter's favourite joke about mothers are, exactly the above two points, and I tell her to wait till she's one.
Her comment reminds me of JA's in this book about Lady Middleton.

I know, one can say 'she could still do this or that'.... but.... I don't blame any woman so absorbed in her children, and her life as their mother.

I think she would be better company for other mothers with children of the same age.

I don't know if JA meant to be critical, but if she did, then all I can say is that she didn't understand this behaviour well enough.

The part where the noisy children come down after dinner;
"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."

Her children know their mother well, and are not among those who are taken to see their mother by appointment by their nurse to kiss her goodnight.