I think you should sit down with your grandmother and tell her exactly what you wrote here. 100% exactly what you wrote here.

You explained it with the right level of emotion and fact, while not being sappy or cold. I think your grandmother would appreciate it.

Once you’re done, tell her you love her and wouldn’t want to hurt her, and you want to know what she is thinking.

You don’t want to leave this unresolved, or you’ll feel bad long after she’s gone.