Maybe its because of FIL. My Aunt A was always lamenting that nobody ever visited her. It was because her husband (Uncle A) was groping all the little girls, so everyone just avoided them instead of telling Aunt A the truth. Nobody talked about Uncle A's behavior until after both Aunt A and Uncle A had died. Then me and my cousins started comparing stories and realized we weren't the only ones and it had been going on for decades. I'm not saying this is what is happening here, but maybe MIL should ask about cold shoulder without her husband present.