I think you sound resentful more than jealous. It sounds like she is doing the things you wish you had time to do, except you have work, a house and a child to look after as well as trying to fit in time with your DH.
Your DSis on the other hand just has work and then comes home, where she has time to chat with your DH, watch tv (think the wine is just basic manners tbh) etc whilst you are ferrying your DC about to hobbies, doing house stuff and everything that goes with being a wife or mother.
From what you have said it doesn't sound like there is anything at all going on that you need to worry about. But it does sound like you don't feel you have enough time with your DH because life and the demands of work, home and DC are taking up time too, and you have become aware of this because your DSis is showing you it.
Perhaps if you were less busy your DSis would talk to you/watch tv with you too? As you aren't available she is chatting to and watching tv with the person who is.
If it's bothering you this much you need to work out ways to get more time with DH. Maybe get your sister to babysit one night a week so you can have "date night"? Ask her to cook one or two nights a week and spend that time with DH drinking that glass of wine and chatting? Get DH to do some of the taking DC to hobbies so you can have a drink and a chat with your sister? Get DH or both of them to pitch in on the household stuff so that you can ALL sit down and chat together once everything is done.
I do think this could all be resolved quite easily. It sounds like you have NO time, and they both have plenty of time to chat etc. Even out the division of labour so that you can have some time to join in, or spend alone with your DH.