It sounds to me like you have a chip on your shoulder...
Today we as a society won't let teenagers do anything. People used to get married and have children much younger then they do today.
On the one hand on this forum we bemoan the young know and do nothings, but on the other hand we blast people who are teaching their children life skills.
The older girls do do a lot of the work but they don't seem to resent it. They will all be awesome moms themselves someday, if they so chose.
I get that impression, too.