How to specify a lover's gender
Solution 1:
You don't need any special vocabulary here. You can simply say:
A doctor’s daughter hides her female lover ...
This is perfectly fine and idiomatic and is probably the closest to the meaning of the sentence in the Original Poster's language. One could easily also say:
- A doctor’s daughter hides her gay/lesbian lover ...
However, this overtly draws attention to the lover's sexual orientation in a way that the more neutral rendering with female does not.
Solution 2:
A doctor’s daughter hides her lover
Two suggestions
- Use the lover's name, e.g.
A doctor’s daughter hides her lover, Janet ...
- Ask on Writing Stack Exchange where people are constantly dealing with the difficulties of writing about gender these days
P.S. You should avoid asking exactly the same question on two different Stack Exchanges, so you could perhaps delete this one, or phrase the new version more generally.