How much time elapsed between getting the number and sending the text message. One thing you must expect when calling/text messaging a woman the first time is that she is highly probable that she might not pick-up/respond. In regard to text message, it all depends on the time of the day and the content of the message. Besides, the message could be interpreted differently when you text message someone. I always avoid text messaging someone the very first time I obtain her number. Maybe only when I'm drunk at the club and just wanted to shag the woman; else, I'll give myself sometime and call her differend day. I always leave message indicating when and where we met on my first call. In your case, since you already know the girl to begin with, you should have callled her.... In any case, first text message should always be brief. It should have gone like this:
"Hey Kristin, this is midnight. I forgot to pass along my number to you the other day on yahoo 360. Long time....."
In this way, she can respond or not. In any case, you were not expecting her to respond anyway. Regardless, she now have your number. Now you can call her.....