Background to situation:
My parents have always played my sister and I off against each other since we were small children, which has lead to an unhealthy relationship. My sister lost her DP 2 years ago after suffering with cancer for 7 months, which resulted in her drinking excessively and taking drugs. They had a DS who was 14 at the time.
my DH and I stepped in to help and support as we could clearly see she was not coping unfortunately this led to a lot of bitterness from my sister and since her DP death cut me off. My parents supported her in this.
The situation now is that my parents are closer to my sister than to me, and my mother is being selective on what she says to me about what she does with my sister.
From my perspective her relationship with her children is how she wants it. I may not like the fact that she’s secretive but that’s how she is. My DH often asks why my mother is underhand to which I have no answer.
I’m now planning what to do for Mother’s Day and other than giving a present and visiting I don’t wish to do anything else - AIBU?