The FamilyTalk plan is what AT&T considers a "grandfather" plan since it's an expired plan that is no longer being offered. There are several FamilyTalk plans; they are: FamilyTalk 550, FamilyTalk 700, FamilyTalk 1400, and FamilyTalk Unlimited. These are shared voice plans servicing several lines on one account. So, say, you have the FamilyTalk 700, and there are three lines on the account, all three lines would share the 700 voice minutes. Now, all three lines select messaging and data plans seperately since FamilyTalk plans do not include data or messaging plans. The point that I'm trying to make is whether it was with your parents' account or yours, if you have the FamilyTalk plan you are going to have to select messaging and data plans independently.
In short: FamilyTalk plans are only voice plans, they do not include messaging or data plans, which are charged seperately on each line.
Best Regards.