IF jealousy is the correct term, I definitely understand why you would feel that way. I think it would a natural reflex to the situation.
Keep in mind that "healthier relationship" is a subjective term.... it may simply mean that THEY get healthier over time when they realize dad isn't changing & they have to stop going to the hardware store for bread. What you THINK would be detrimental MAY actually be working to help them get to their greatest good. They may need to jump in & out of the rabbit hole a bit before they recognize that it hurts them to do so. It's so hard because they aren't quite adults but they aren't babies.... they still need guidance but are working on being independent.
You CAN DO THIS Butterfly, I truly believe that you can. I see how helpful your posts to others are & I know you are so much more capable than you are giving yourself credit for right now.
