Help

My adopted brother found us about 20yrs ago all was fine for a few years then about 12 years ago the relationship broke down we haven’t seen him since . I reached out to my brothers wife on fb (a few days ago) she has a closed profile she excepted , when I read her posts I found out my brother died 3yrs ago . My stepdad died 7 years ago my mum has been broken since .So my question is do I tell my mum and break her heart again or just say nothing