My mum's phobia for polygyny

I called my mum a call the day after eid because I was too busy to call her on eid day. After the usual exchange of pleasantries and asking about other members of the family and her telling me how the eid celebration went on their end, she told me there is a problem she needs to discuss with me urgently, because she is really disturbed. I was scared by this line of opening and braced myself up to receive the sad news. Well, she said its all about a brother he knows, who she heard had taken a second wife just few years after marrying the first. (edit; it so happened that my mum misinformed and the brother did not remarry! at least not yet.)

Apart from feeling sorry for the first wife, my dear mum had another thing to worry about; she said as the brother and my hb are very close friends, she is afraid he would take his lead and soon get interested in marrying another wife as well. Now if my mum is scared of anything happening to her daughters, it is the very thought of any of us being married upon by our husbands. I mean shes scared to death of this that at times I hope it does not ever happen to any of us when she is alive, just for her sake. My mum's paranoia is not just out of the sky, its because my Dad married another wife thirteen years after their own marriage to be able to get himself a son as my mum had six girls. But Allah, the gracious lord blessed her with a son two years after the second wife had a son, but then, it was too late and she became a permanent picture in her life and marriage and my parents relationship has been rocky since then, even though the second marriage has been on for almost thirty years. They never divorced, but they don't live together either and my dad lives with his second wife and their six children in another town, so that means my mum is pretty much alone even as I type this, because my father visits her like once or twice every month. My mum is in her early sixties, so its not so bad that she is all by herself in the house most of the time except when my sister and her family visits, or when my undergraduate kid brother is not in school. But I cringe when I think of when she gets older and needs someone to talk to, someone to share her thoughts and feelings with, or just someone to sit with and enjoy a nice meal...