Just to add my two cents – I also have a competitive sister and also a colleague who behaves in similar ways. I decided years after years of getting frustrated by their behavior that there are really two options: to stand up and fight my corner or opt out of the competition as much as possible, neither of which is very satisfactory or resolve the problems. With my advancing years I do think there’s another option which is to redefine success for yourself.

I think first you have to figure out what you’re afraid of. I think your biggest fear is missing out so perhaps if you could move your focus elsewhere – to your own family, your job, a tight circle of friends or even acquaintances who are passionate about the same things as you – then you wouldn’t care quite so much. The other thing I read once is that anger or hurt is a sign that someone has overstepped your boundaries ie the things that really matter to you. Those boundaries are really important – you need to protect them and if that means emotionally stepping back from your sister and your whole family then that might be the right thing to do. You sound like a great person – I wish you the best of luck!