We haven't seen her in the show so far and maybe we never will, but we can speculate. That is what this thread is for, so write what you think

I really hope that we get to see her at one point, or that it will be at least implied that she is somewhere.

I think she is simply living in another city

I've read many stories where the unicorn is an orphan, so it got me thinking about the human as well. Some say she died and shrug it of that easily, others like you say, she might live in another city and then there are the crazy theories I love :D

the crazy theories are always the best ones XD