I'm very surprised they are not getting vocations. I always took it for granted that religious orders who lived good holy lives would be blessed with many vocations.
I think groups of people, like a specific Carmel are like individuals. If a person does the right things then God blesses them. This is scriptural. So I would expect a good Carmel to get good vocations. Just as I would expect as a matter of course I would expect good parents to raise good children. A good tree , as Jesus said , brings forth good fruits. Or, as the old saying goes, an apple never falls far from the tree. Mostly, although not always, the parents of saints are holy, good people.