how to check if she has seen my messages on fb?

[Gokul]

Hi.. I've been talking to this girl from US for about one year on yahoo messenger. But since some three weeks ago she stopped receiving my messages and she keeps on asking me am I there etc and it really pisses me off since I'm replying her but she is not getting any of it. So I found her fb profile and messaged there. We had not added on Fb each other as friends coz of her annoying family so my messages were going to her other folder and not inbox. So there was no way to know if she has seen my messages I guess. And then I decided to spend 1$ to send message to her inbox directly according to this stupid modified policy of fb but its going to be one day since I sent but I'm not sure if it's gone to her inbox or not. This really makes me frustrated and I would like to know if there is any way to check if she has received my chats on yahoo messenger and also on Fb. She still used to write me are u there etc and I become more mad that I can't talk her coz of this stupid network. Pls somebody help me to find a way to get back to her...thanks in advance...