You can still change it, Nell. People do after longer than a year.
Most clients know that we don't use our real names, so they understand if we want to change, and if they want to keep calling you Nell they still can if you don't mind. The only problem is making sure people who know your old name can still find you.
If you're only just getting a website it's a good time to revamp your image, and you can state on it that you were previously known as Nell. Get a new email address and set your old one to auto-reply an explanation or forward all emails to your new address. See if you can comment on your old reviews (some sites allow you to do this as a right to reply, but you could probably use the system just to say you have a new name and website). Post on any message boards that you've changed your name, it might even get you some extra attention.