Not every sci-fi romance has aliens, but of those that do, I go in expecting either the hero or the heroine to be one (or even both). I don't have an expectation for just one type of alien character. So if the heroine is an alien, cool.If you know of any sci-fi romances or romantic SF stories featuring an alien heroine and human male pairing, let me know and I'll add it to the Goodreads list I started: Alien Heroines in Sci-Fi Romance/Romantic SF.
Perhaps I'm an outlier, though. It's interesting to note that Goodreads has a list of “Outer Space Heroes Sci-Fi Romance” and “Best Alpha Male Alien Meets Human Heroine Romance,” but for the life of me I can't locate a similar list for alien heroines. Something's telling me that alien heroines aren't familiar enough to readers. I wonder why?