I've held my tongue though, for I can see Marilla doesn't want advice and she thinks she knows more about bringing children up than I do for all she's an old maid.

But that's always the way.

Folks that has brought up children know that there's no hard and fast method in the world that'll suit every child.

But them as never have think it's all as plain and easy as Rule of Three--just set your three terms down so fashion, and the sum'll work out correct.

But flesh and blood don't come under the head of arithmetic and that's where Marilla Cuthbert makes her mistake.
I suppose she's trying to cultivate a spirit of humility in Anne by dressing her as she does; but it's more likely to cultivate envy and discontent.