She said she knew and that she doesn’t agree with my mom’s priorities and that my parents are too liberal.

"Doesn't agree", not "doesn't approve". There's nothing wrong with disagreement. Clearly OP and Rachel don't see eye to eye, but to make her out to be some "tactless" person because she disagrees is simply insecurity with truth. She didn't shame, she simply said her point of view to a mother she disagreed with. Is it a losing battle? Yes, but I praise her for not being afraid to speak her mind and there's nothing wrong with that.

And to your other point that it's none of her business. Her boyfriend's parent's choices are every much her business as it is his parent's business of her choices with their son. They're all adults. Short of an unfortunate illness or injury, aging poorly is a copout. Truth. You either hold it together for your marriage or you let your shit come off the rails. It is "altered reality" thinking to believe it's not and it terrifies me to believe that 38 other people agree with you. She didn't treat her "crappy". If you get hurt with truth, that's your own problem and that's what makes you a Sensitive Sally.

All of us are judgmental. It's ironic that you say she's a judgmental asshole and yet here you are calling her an asshole and inferring I'm crazy for coming up with a term. Some people are attractive. Some people have kids later in their life. Deal with it.

And, to your other point. I don't think it's ok to treat people badly just because I don't find them attractive—I really could care less if they want to care about investing in themselves and creating value in their world—but Rachel never treated them poorly. Her stating that they aren't as attractive as one another is pure statement of her belief. Is it wrong to call it like you see it?

I'm not gonna win this argument with you because you're just as sensitive and it's this altered reality you all want to live in. Unfortunately reality is real and it's slightly terrifying that you can get along in it by dismissing it.