To be honest Callistemon none of us knew who she was before she became Harry’s girlfriend. It’s not surprising that a charity based in Canada used her to raise their profile, after all, she was living and working in Canada. Possibly quite a few Canadians watched the tv show she was in. Here in the UK many people watch EastEnders or Coronation Street and are aware of the characters in those shows, although they are not particularly famous. I imagine Meghan fell into that category, not particularly famous, but known in Canada by those who watched the show.
As for me, I had never heard of her, I didn’t know her from Adam! Had anyone else on here heard of her before Harry?
As for Catherine, I’d never heard of her before William. William made her famous. The same for Meghan, Harry made her famous.