Nellje, @Emily_Coles responded to and answered your question where you asked the question which was in Emily 's "Website Update: second week" topic/discussion. I have linked to Emily's answer below so people can follow the link to read her complete answer if they want to.
A note about the
@ operator. You have to use the full username of the person you want to notify, not just their first name. Currently TuDiabetes has at least 6 usernames which begin with "Emily" — there is Emily Cole and five other people. The person you notified is an Emily who lived in Ottawa, Canada. She apparently joined Tu on Dec 20, 2007. Discourse does not think she has been active since her post on Dec 23, 2007.
Using the full, correct username should not be as hard as it might seem since Discourse should prompt you with a list of usernames which match what you have typed after the
@. I have included a screenshot illustrating this below.