Similarly, other kinship titles like grandma, grandpa, aunt, and uncle are capitalized when used in place of a person's name but lowercased when used as common nouns.
Do you capitalize my uncle?
In a title, “uncle” is capitalized.
When used generically in a sentence such as: “my uncle said to visit her,” then the word “uncle” is lowercase because it is a generic noun. Correct: The other day I went shopping with my uncle. ... This is also true when asking a question of your uncle. Correct: My Uncle Jim is the best.
Are titles capitalized?
According to most style guides, nouns, pronouns, verbs, adjectives, and adverbs are capitalized in titles of books, articles, and songs. You'd also capitalize the first word and (according to most guides) the last word of a title, regardless of what part of speech they are.