Too close for comfort

So, I work with a woman who dated my step father's son. So random travel to another state to work for a company for years and learn if this connection over dinner. My step dads son has real issues and conmunicated his issues and it always seems to come up when she talks about him. I'm finding myself talk about my family at work when first off it's not my family really. Things are really one sided. But it's in my safe place. Very funny. Very concerning cause I'm sure she know something about my brothers trials and tribulations but u know for certain it's not in the proper context. One thing I learned about his son, he has no loyalty. Not to his father or brother. Strange concept to me. I must pray on it.