There was no uniform age limit for the authors of romance novels. It depended on the author's personal thoughts and writing style. Some romance novelists might be good at describing young love while others are better at describing the love between mature men and women. Usually, the author of a romance novel would not be too old but not too young either because writing required a certain amount of experience and experience. If you want to write a novel, you can first consider your own story ideas and theme and find experienced ones to improve the quality of the novel.