You have no personal relationship with this woman, yet you think you know exactly what her life is. You don’t know her life, I can promise you. You may want to speak to a therapist about this, especially if your child is coming to you with the same issue and you don’t know what to say.
There is always going to be someone who has more than you, and someone who has less. Instead of comparing in a negative way, perhaps try to be grateful for what you do have. If you want what she has, go get it. Make a list. Start taking baby steps, and seriously, as an adult you know comparing yourself to others will always make you feel bad, so why do it? You’re on your own path. Stop assuming you have everyone dialed in.