How to deal with a sister who is bitter about my relationship?

I recently reconnected with my sister who I haven't spoken to since 2022. She was mad at me for leaving my ex who was abusive towards me (she didn't know at the time) but when she found out the things he did she was still mad because "I had someone and she didn't" I met someone else not too long after that and she was even more upset because he is better than my ex and once again she has no one. We spoke a few days ago for the first time since 2022 and the resentment came back when she asked if I was happy with my boyfriend and I said yes. I want to have my sister back... but it seems me not being bitter like her is a big roadblock.
How to deal with a sister who is bitter about my relationship?
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