Disappointing Thoughts About Sister

I’m turning 2 years sober in June and I’ve invited my family to a soberversary party at my house.

My sister has said she can no longer come as her 5-year-old has a birthday party for one of the kids at her school that day. I feel disappointed that she’s not prioritising this over that. And I am aware that it’s my thoughts and I’m confident in working through those.

My question is – when should you tell someone your thoughts about something? My thoughts make me feel disappointed, not her actions – but I’m unsure when expressing that I feel that way is productive or if it’s going against these teachings and making her responsible. I want to come from a clean place in whatever decision I make, so would appreciate your help!