Q&A with Reign Author of Dilemma Series discussion

Someone asked me where I got the idea to write "Tiffany's Dilemma: A Matter Of Time." Well, the idea came from my 19 years old son, Brandon. He and I had a mother and son lunch date and he told me about his oldest sister's friend Tiffany and how he had a crush on her when he was a small child. I asked him when did the crush start and he told me as long as he could remember. So I asked were you six or seven and he said younger. I found it amazing that he even felt such a strong emotion at such a young age. Anyway, I added a few "what if's" to the young boy crush idea and keep the characters ethnic backgrounds the same. I even keep the names of the characters the same as well. So, thanks to a little boy's crush the story of Tiffany and Brandon was born. I have on dilemma with the story.... how much of an age difference is acceptable? I'm doing a final edit before publishing and I'm still struggling with this issue. What do you think?