Run it by my sister to have my adult nieces visit?

My sister does not speak to her adult children very much as her relationship with them is not the greatest. When she talks to me about them, it is usually what they have done, wrong, etc. They are 23 and 19.

I invited them to visit me soon and I paid their way.

My sister has decided not to speak to me anymore because I did not run it by her first.

I didn’t think I needed to. They are adults and they are my family members too, I have a decent relationship with them.

If my sister invited my children to visit her, I wouldn’t say “why didn’t you run it by me first?”

I guess because she has a bad relationship with them that I should have?

So what my sister now is a bad relationship with her children and me.