I admire the sensible steps your family took. Very restrained.
In all honesty, hubby initially wanted to by pass most of the steps we ended up taking. The rest of the family had to convince him that SIL was not worth doing time. We were all in agreement that whatever it took my daughter would not end up dead.
We did make contact with LE, and also battered women’s shelter as part of the overall plan. Being realistic though we knew WE had to solve the problem- LEOs are too restricted in what they can actually do to ever think any other way.