The Flower Queen: A 1970's Suspense Romance

It began with a dying husband and it ended in a dynasty. It took away her husband's pain on his deathbed, kept her from losing the family farm, gave her the power to build a thriving business, but it's illegal to grow in every state in the country in 1978. It even brings her first love from high school back; the only problem he works for the FBI. Will their occupations implode their romance or will the opposite happen? Asecond chance at love, opposites attract, rags to riches heroine trope story.