In English there are no masculine or feminine forms. English uses gender specific nouns for male or female.
The noun 'press relations officer' is a common gender noun, a word for a male or a female.
The feminine form of a press relations officer is a press relations officeress.
Public Relations Officer
Ero una poliziotta.
The feminine form of alumnus is alumna. The feminine plural is alumnae.
The feminine form of ami is amie. The feminine plural is amies.
Mistress is the feminine form of master. It is already in feminine form.
The feminine form of a baron is a baroness.
The feminine form of bajo is baja. The feminine plural is bajas.
The feminine form of charmant is charmante. The feminine plural is charmantes.
The feminine form of benefactor is benefactress.
The feminine form of groom is bride. The female partner in a marriage.
The feminine form of the name Ronald is Ronaldine.
The feminine form of the word "count" is "countess."