Did my mom block the number without me knowing somehow?

My mom and my grandma haven’t been getting along. They have been arguing a lot. And now they don’t even talk to each other. My mom said she blocked her from her phone.

My grandma pretty much raised me. And she was always someone I talked to when I had a problem. But lately, whenever I text her or call her she doesn’t answer me.

I’m on my mom’s phone plan. So my question is, could my mom have blocked my grandmas phone number from all of our phones on the plan? Is that possible? Cause I know my grandma wouldn’t not answer me for a long time. And that is something my mom would do if it’s possible. But if she did that would be messed up because I’m 24 years old and I can talk to whoever I went. Including my own grandmother whenever I want.