Was I wrong for blocking her?

Me & my sister have never had a good relationship. I’m 23 & she’s 37 & my whole life she was half in half out & when she was in she would try to act like she’s my mother which frustrated me, when she was out she would constantly put her boyfriend’s sister (who is the same age as me) over me. When I grew up & moved out I didn’t speak to her at all but every time I would speak to my mom she would inform me how she’s constantly talking shit about me. Recently a few months back I decided to make amends & I had her on my instagram account but I found out she was STILL getting on the phone with my mom bashing me & I thought that was really fake because she would get off the phone with my mom & be messaging me on Instagram & commenting on my things all is well & we’re close. I don’t like plastic shit I would rather someone admit they dislike me & stay away from me instead of being two faced. So I blocked her. My mom calls me today saying my sister is asking her why I blocked her, I said mom she knows why & hung up. Am I wrong?