I think a lot of the responses here are extremely unhelpful and just dig in and question whether the statement is true rather than addressing why this might happen. Why not just respond as if everything being said is true and give advice on how to deal with such a situation? Is that not what is being requested?
Maybe the truth is that a lot of the woman on this thread do treat other women badly for the same reasons. It's sad when we live in a world which devalues us as women yet we make it worse for ourselves by using any opportunity to tear other women down.
Unfortunately we do live in a society puts a lot of value on the way women look and brainwashes us into tying our self-esteem with our physical appearence and trying to look like what our culture tells us is beautiful. Nobody is in fact 'beautiful' according to today's standards because the only way we can get there is by feeding the economic system and buying all the products we are told to buy.
Not all men will be attracted to a women because of her physical appearance and there are individual differences in their perception of what they see as physically attractive. Just like women. My friend might consider a guy to be good looking and I will not.
Regardless of what a women actually looks like, she may feel extremely insecure about her physical appearance especially after having children. Her partner may or may not have a role to play in the way she feels about herself but like all feelings, they stem from our own thoughts which may also be rooted in past or present individual lived experience. It will be different for everyone.
If someone fears their partner will cheat, he has cheated or a woman is triggered because she has been cheated on in the past, this may cause her to feel an uncontrollable sensation of jealousy everytime the man is around any woman she views as attractive.
In her head she could be constsntly living in a state of unhappiness and stress because she not only is dealing with the thought of her parner cheating or prefering other women over her but may also constantly be looking at other women and comparing herself to them physically.
A woman who is happy with herself and secure in her relationship is not going to care even if Angelina Jolie showed up, fell at her husband's feet and begged him to spend the night with her.
She would expect him to do the right thing and tell Angelina not only that he is not interested in her but but also that he loves his wife.
The reality is that most women are not happy or confindent in themselves and many men are very far from decent human beings. We all have to try our best to find our own happiness with the cards that we are dealt and for some women especially where children are involved they may decide that staying in a relationship that is far from ideal and trying to work on it is the best choice currently available to them.
Having genuine empathy and not taking the perceived jealousy personally and understanding that they themselves might have difficulty controlling how they feel, would be the best way forward.
You can't control how another person feels and sometimes they can't control or hide their own jealousy.
The only thing you can do is not to behave in ways that don't make it worse. You don't have to chat and be friendly with the husband/partner. Even though you know there is nothing wrong with what you are doing and that person is behaving irrationally. You can talk to her and show an interest in her and discuss female related topics, talk about your partner if you are not single, share your difficulties or insecurities to take her out of her own head.
Maybe jealousy has made it difficult for you to form genuine female friendships and because women see you as a threat they leave you out, which can be a very lonely place. Maybe you have been harassed or objectified by men but felt you needed to stay with a man because your female friends lacked loyalty towards you, having seen you as competition. Maybe you found friends in your life whose only reason for wanting to be near you was to access the male attention they so desperately craved but never got and then once they got access to the men who you were more able to draw in, they ditched you because they were scared those men would prefer to be around you. Maybe you wanted a man who loved you for the unique human being that exists inside you but ended up attracting shallow, self centred men who didn't treat you as a person but as a shiny object or a trophy they could parade to boost their own ego. Maybe you felt that they really loved you but they didn't actually notice and care about your goals in life, talents or mutual interests because their desire was all about the way you looked. When females rejected you, in your loneliness you searched for male company but then even the really nice guys who you thought were genuinely your friends decided that they also hated you because you just wanted a friendship and they thought their kindness entitled them to more.
If you have experienced any of the above, sharing those genuine difficulties may help to build understanding. We all suffer as woman whether society views us as physically attractive or not and there are issues that arise from both. It's only by breaking down those walls built up by our own egos and concern with ourselves we can step in another person's shoes, help ourselves and help another and genuinely work together in building a better world.
You can't control how another person feels. If you make an effort to be kind and understanding and are met with a cold response you can just keep your distance and stop being so concerned about what may or may not be going on in someone elses head ( we never truly know).
Often when we have an experience and we get it into our heads that this is something that happens to us, we find it will continue to happen. It's our thoughts that shape our actions, words and feelings. In shifting our perception on the scenario and getting out of our feelings we can change the reality and build bridges between ourselves and our fellow human beings instead of walls.