User names must be unique and you can check for usage with the "Members" tab in the upper right had corner of the screen. Nicole is a long time regular user so that name is clearly not available. Ashley is also used but hasn't been on in about 4 years so it's possible that the name could be reassigned to you. I would need to ask if the old account can be deleted.
If you have another name or a variation on the name other than the above names that is unique, we can use that name.
You will need to verify that your email address is correct as the name change takes place in two parts and the second will require an email verification. Until you receive the email, you will continue to log in under your old name.
Let me know how you would like to proceed with the name change.