Is it mean I locked my grandma out of my parents' bedroom?

She was using their bathroom on the 2nd floor even though she has her own one on the 1st floor of our house. My mom left her make up and all this stuff out on the counter so I locked the door because my grandma was being snoopy in their IMO. She's usually like that and it irritates everyone. Plus why walk all the way up stairs to blow your nose in a bathroom that isn't yours that you're usually off-limits from..................then try to get in again?