It might. they had a school. King was having a problem getting his kids accepted. Julia’s parents accepted them.
So it isn’t like there was no connection between the two families.
I call BS. Maybe the King’s tuition money for their kids ENABLED the Roberts parents to pay their hospital bill, but I doubt that the bill was even discussed except in those terms — “I’m so grateful y’all enrolled your kids when you did — we didn’t know how we woulda paid the hospital without it.”