It's important to look at the actual paperwork. I won't say that a father couldn't be disowned by some meeting for failing to control his adult children, but it doesn't strike me as typical. Based on what I've seen and read, I think it more likely that Sarah Boone's father was disowned for some action he took to help his daughter marry out of unity. If he attended the wedding, for instance, that might have been frowned upon. But check the meeting records to confirm the specific actions that led to the disownment. It strikes me that some posters admire people who defied their meetings. That's in keeping with the modern sensibility that satisfying the needs/wants of the individual is more important than adhering to group rules. We can argue about whether the specific actions merited disownment. (Personally, I think the crusade against marrying out went too far.) But it's worth remembering that church discipline is what allowed the Quakers to make a remarkable impact on the world -- most notably in the work for women's rights and anti-slavery. Mark Whan Daniel Boone's oldest sister, Sarah, married out her father was disowned.