I don’t mind “less feminine” names for girls, but I really can’t get behind surnames as first names for either gender.
Lennon in particular is so tied to one specific public figure (unless people mishear it as “Lenin” and then it’s an entirely different public figure).
What about names like
Carmen,
Tamsin,
Ingrid or
Liorit? Something can be strong, simple and unfrilly without resorting to borrowing from the boys or using a trendy surname.