How does Marmee's attitude about Meg and Mr. Brooke and her children growing up in general illustrate Alcott's progressive views on the position of women in the late 1800s?

Marmee, to Jo's surprise, doesn't mind Mr. Brooke courting Meg at all. However, she doesn't want Meg to marry until she is at least twenty. She thinks that all of her girls should know their own minds before they marry. In the 1800s, when Alcott was writing the book, women often married young, so that attitude was very progressive for the times.