I'm writing a ficional story about a historical figure. My MC takes twelve years to achieve a major success. But the bulk of the work takes place in three stages: at ages 17, 23, and 29.
I have divided my book into three parts... but no matter what I do, it feels jolting skipping the time gap.
The quirks that the reader will find endearing when the MC is 17 suddenly vanish when we skip to when she's 23. The things important at age 23 are meaningless at age 29.
I tried writing chapters to fill the gaps, but adding a chapter at age 20 made it worse. Beta readers hated it even more. The reader would fall in love with the MC at age 17, skip to age 20 and feel like they don't know her, but not spend enough time to grow to like this "new" MC before we were off to age 23.
I also tried to write one chapter for each year, and this was also bad. The reader spent too much time in limbo before they could settle down a MC they could connect with.
So, I feel like I'm having to choose between writing an entertaining story and rewriting history. If I made this complete fiction and less history, I could speed up time and make the MC accomplish an impossible feat in a span of 2-3 years. It would be more pleasing to read, but it would lose the lesson I wanted to teach in thr first place: sometimes, you have to labor for twelve years to achieve success.
What can I do to fix my story?