They could just marry these JBs back in the day, it was completely normal and open. Now... it's another story. In some countries, you can still marry someone at that age, even under it, under special circumstances, even in countries where such thing is not normally allowed and the marriage age is higher.
Many parents in USA actually, practically sell their 10-12 year olds daughters to marry rich people from other countries for benefits. So yeah, still happening, but in other countries where it is not openly allowed it happens all inside it under special circumstances.