driver
Specifically "feminine" terms for various professions are falling out of favor in English, "driver" is perfectly fine for either a male or female person who drives. I'm not even aware of there ever having been a feminine form of the word; "drivress" would probably be the proper form, but I can't find any citations for that ever having been used seriously.
The feminine form of ami is amie. The feminine plural is amies.
The feminine form of bajo is baja. The feminine plural is bajas.
The feminine form of alumnus is alumna. The feminine plural is alumnae.
Baroness is the feminine form.
Mistress is the feminine form of master. It is already in feminine form.
yes
The feminine form of charmant is charmante. The feminine plural is charmantes.
The feminine form for host is "hostess."
The feminine form of benefactor is benefactress.
The feminine form of "mauvais" is "mauvaise."
Ta means "your" before a feminine, singular noun.