I think the less restrictive orders have less requirements on age…I saw this on an EWTN show on vocations. The ones like Mother Angelica’s are so strict that you probably would start to go crazy after a couple of weeks (that is somewhat what she said). Being told as a 40 year old what to do, where to go, when to speak,etc. might be okay for a while, but then your personality and stubborness would kick in. In another book I read from an older nun, she said being treated like a child as an adult is very hard, most older women leave…it’s a nice retreat, they enjoy certain things, but a day that “isn’t their own” from morning until night, is easier to adjust too as a younger woman. Men find the same thing…there are exceptions, but many times the same thing happens. Orders that are active, with prayer and meals together, but you do different things during the day, are easier, but you still have to deal with the obedience factor.