Hi Zach,
It is most likely a bad sign if she hears that you look like her boyfriend with better eyes from her friends.
She is being reminded of her boyfriend every time she hears that.
Hence, she will naturally get really quiet or nervous if she is worried about her boyfriend finding out about the fact that she talks to you through social media and a webcam.
Even though you believe that she thinks that you are attractive, she has a boyfriend.
It would not be wise to continue interacting with her in a romantic capacity or with romantic hopes.
You would only become more and more emotionally attached if you do and this could lead to heartbreak.
If she still gets nervous when reminded of her boyfriend, she is indicating that she worries about losing him.
Hence, the likelihood of her leaving him for you at this time would be slim.