A few ideas:
[name_m]Noble[/name_m] (I see this as more masculine, but I think it could work for either gender, and [name_f]Dorothy[/name_f] [name_m]Noble[/name_m] [name_m]James[/name_m] is lovely! [name_f]Audrey[/name_f] means “noble strength” so I think this would work well (or any other name meaning “noble” or “strength”)
[name_f]Maeve[/name_f] or [name_f]Esme[/name_f] (or any other name with the [name_f]May[/name_f] sound!)
[name_f]Alma[/name_f] [name_f]Maude[/name_f] (or any other double middle that uses the initials AM?)
[name_f]Margaret[/name_f] or [name_f]Mary[/name_f] or [name_f]Mabel[/name_f] (traditionally the names that [name_f]May[/name_f] gets a full name for)
[name_m]Or[/name_m] maybe there was some aspect of your grandmother through her personality or life experience that could give you a touching tie to her? [name_f]My[/name_f] grandmother’s middle was also May/Mae and pretty much half the girls in the family got named either her first name or Mae… I was not keen to follow suit (although I love her first name now lol). Two of my favorite ways to honor her were [name_f]Lily[/name_f] (at her funeral I was given a lily and it felt like her last gift to me, I love lilies because of this!) and [name_m]Boaz[/name_m] (her first name was [name_f]Ruth[/name_f], and I like the tie to the Bible story). I love these names because they feel like a special tie to her, but not one half the others in my family will have! Maybe something like that could work for you?
Good luck!