A Rejection Letter

I was doing a bit of de-cluttering the other night, and I came across a rejection letter I'd got when I sent off my first ever novel to an agent.
It was a very kind rejection letter, pointing out that I'd improved no end since I'd first submitted the story - which finally became Like Father, Like Daughter, when I decided I couldn't improve it any further, so I'd throw it out into the cruel world to see if anyone else would like to read it!
However, the suggestions the agent made for improving it further seemed to hinge on turning it into a contemporary story where the central theme was about a teenager choosing between her divorced parents. The agent didn't think that the fantasy world was necessary to the story I was telling.
Having Arian making the choice between her parents is important to the story I wanted to tell - but like Joy Chant, who wrote Red Moon and Black Mountain, when I write, it's fantasy that comes out. I have no interest in contemporary, 'real-life' situations when I'm writing - and I'm not sure how I could take out the fantasy elements of Like Father, Like Daughter to make it into something set entirely in this world. They're kind of integral to the plot.
At one point, very early in the writing process, I did have the vague idea that Arian's father Mal could be imagining all the alternative world situations, but I really didn't have the skill to pull that off - anyway, I wanted the fantasy world to be real, and not delusional - and I didn't want to send poor Mal mad. He had enough problems to deal with already.