You've heard of Catholic guilt, haven't you? There's JW-guilt too. That's one factor.
Also, JW children are NOT encouraged to develop independence and grow apart from their parents. On the contrary, they are encouraged to doubt their own minds and depend on the organization and their parents for counsel. It is not at all unusual around here to see a forty year old adult child finally breaking away. One poster suggested that adult JW children are stunted in their maturity.
It doesn't sound like Gracie OR Lynda have thought very deeply about where they want their lives to end up. It's much easier to let others take charge. Then there's someone around to take the blame if it doesn't work out.