I think that maybe, instead of "jealous", some of the other women are envious of LVP.
Yes, they all have certain levels of wealth, but I think LVP has the most personal/marital net worth, except maybe Camille. Teddi, Denise and Rinna do not come close. Of those three, I think that Rinna is very envious of LVP - not just her wealth, but just everything about LVP-businesses, lifestyle, marriage, etc. Denise hasn't been around long enough, but I also think she wouldn't be envious, just because she always seemed kind of baked and out of it. I do think that Teddi is envious, not just of LVP, but of the the other ladies, as well. She definitely wants what they have. Dorit, as we're learning, has a bank book filled with deposits written in disappearing ink, so she could be envious of LVP's money, but I also think she is envious of LVP and Ken's relationship. Kyle - I don't know - I don't think she is envious of LVP, but I do think that Kyle is a "keeping up with the Joneses" kind of person living in Beverly Hills. I don't think Erika is jealous or envious of anyone, because I don't think that she really cares too much about any of the ladies.
I don't think that age defines whether one can be or would be jealous or not. I live in a fairly new and pretty upscale 55 and over community, and I can attest to the fact that women in their 50's and 60's can, indeed, be extremely jealous and envious of others and what they have, as I witness it every single day. In some ways, it's worse than middle school here!