You could have just submitted the first 3 chapters, but it should be ok, so long as you've reminded her of who you are in the body of the email, rather than in an attachment. If the latter then the email is liable to be deleted if they don't remember you and assume it's just an unsolicited submission from a stranger and their submission guidelines state postal submissions only.
As with any submission expect to wait up to 3 months for a reply.
Meanwhile you may as well get submitting to other agents, rather than sit there twiddling your thumbs.
Good luck.
- NaomiM