I dont think there is much you can do about that situation. All those involved are adults and can take responsibility for their actions. An important thing to keep in mind, especially with it being family, Is not to be judgemental or to Interfere. Another thing with family is you have to be supportive of their decisions regardless of if you think those decisions a are right or wrong as that is what family does. My family members were not supportive mostly as I am the 7th of 7 children, and lost our mother when I was 6 so we were all farmed out to related families hence a close family bond was never created. Fortunately for you you have that strong bond and applaud you for it.