Narrowing My Niche

Hi All and Happy New Year! This is my first time posting in the business section of Ask Brooke. I hope I came to the right place! I chose for my impossible goal to build a successful freelance writing business and quit my day job by the end of the year. I currently have one client, for which I write on a variety of topics including human interest stories, town events and movies. I keep reading and hearing that our niche has to be very specific, but I’m still figuring out how to apply that to my business. As I mentioned, I’ve written on a variety of topics, I’ve also freelanced for a greeting card company and I edit and proofread. If I narrow this down, won’t I then be limiting myself?
Any insight you can offer is appreciated. I promise, I’m not indulging in confusion 🙂 I just really want to be clear on the best course of action for my business
Thank You So Much!!