-elle is not necessary a diminutive. In theophoric names such as "Arielle", "Michelle", "Michele", "Gabriella" and "Gabrielle" it is derived from the Hebrew El, a name for God.
Another commenter believes, in Romance languages, that the "-a" feminine gendered suffix is diminutive compared to "-o" masculine or neuter suffixes, but that is not true. Not for Latin, or Spanish or Italian or even Greek.
https://en.wikipedia.org/wiki/Gabrielle_(given_name)
Another commenter believes, in Romance languages, that the "-a" feminine gendered suffix is diminutive compared to "-o" masculine or neuter suffixes, but that is not true. Not for Latin, or Spanish or Italian or even Greek.