I've had similar issues in the past.
Possible reasons
1) She's missed your emails and deleted them
2) She has confused you with someone else and thinks you're one to avoid
3) She has seen you are on this forum and won't see you
4) She is too busy to take new clients
5) she's been ill/on holiday/started a relationship
I wouldn't let it get to you at all though, just chalk her up, delete her from your hot list and move on.
or if you really want to meet her, send one final email, very politely asking if she is ignoring you for a reason? or if you've upset her in some way. That's worked for me in the past.