Is the suffix "-ette" used for referring to a female?

The -ette suffix is normally applied to women, not objects designed specifically for women. Thus suffragette, your dudette, usherette and the like. The French language uses -ette to feminise names: Paul/Paulette, Claude/Claudette, etc., and the same principle is used to feminise some nouns in English to create a female variant.

By extension it can also mean "small", cigarette, novelette, Nissan's Vanette and so on. These aren't female, or specially for women.

It's not normally used to create a noun like scooterette meaning "a scooter for women", although perhaps it's simply a smaller scooter which happens to appeal to women (and not men, so it's ridden exclusively by women).

There are also majorette and usherette, but -ette can be a diminutive suffix, used to produce words such as kitchenette and cigarette. It is also sometimes used to describe imitation material such as leatherette.

its generally female because of its etymology: From the French -ette, the feminine form of the diminutive suffix -et.

-ette is frequently used to indicate the fairer sex. As in bachelorette, suffragette, etc.

-ette
a noun suffix occurring originally in loanwords from French, where it has been used in a variety of diminutive and hypocoristic formations (brunette; cigarette; coquette; etiquette; rosette); as an English suffix, -ette forms diminutives (kitchenette; novelette; sermonette), distinctively feminine nouns (majorette; usherette), and names of imitation products (leatherette).