The 5 children produced 16 grandchilden between 1955-1990. So far there have been 6 divorces. So not 50%, but close. And there is still time to get that percentage up.
Going off of my family, my grandparents have 12 kids, that have ~50 kids of their own (my cousins).
Two uncles have gotten divorced.
One uncle’s a priest.
One aunt has two kids, never married.
I don’t think any of the cousins have gotten divorced, though I’m one of the oldest at 29. No major issues that I know of yet.