I have a feeling she was Derby.princess or Derbyshire Princess - something like that anyways. My reasoning is that this profile appeared in my HLand I'm 95% sure I had Derbyshire Princess (or whatever) in my list previously.
When you add a new profile in your HL, try and also note down what she calls herself and her location, reasons:
1 You can track how often she changes her username (I tend to note down the date I added her to my HL and dates she changes her username).
2 Per your case, if they re-appear in your HL, you already have noes stored against her.
3 Regular change of their location usually means a PG scam, unless it is obvious she is touring around and picking up feedback.