My mum is jealous of everyone!? ?

Yea the title says it all she is awful and I'm suck of it Idc care if shes jealous it's just the fact that she can't see it and I have keep telling her to shut up! Like she comes out with whatever she wants and didn't thunk about it then if she hates a person she's cheeky to he'll to them like we have Canadian cousins over and she hates them (why I'd she jealous of everyone?) and they were talking about food and my mum says your not getting anything you gorges and then when they talked about going placed (when they are on holiday) she was all your not going anyway in a stern voice ? Im sock of this because of them I've had to consistency tell her to shut up lately and I'm worried as I really don't want a fight on my simmer holidays! And people are defibatrly getting annoyed as they are biting their tounges And I think she's ruining theit holiday as they are going to a hotel for the night! I don't know what happened to my mum but she's awful she used to ve nice but now it seems that everywhere we go she finds someone to be jealous of and now that I think of it she's always had this like shed always complain in the shop etc and she's had this mentality always say what you think and I think this has effected it! If she knew thus you'd probably die she didn't realize how ignorant she's being I don't think! How can I stop this how can u get her to stop being rude!