From what you wrote it seems to me that your co-worker is a narcissistic person, I think your assessment is correct, she was just seeking for attention/admiration to boost her ego. It’s a nasty manipulation/game that narcissists do. Narcissists are usually extroverted, very likeable by everybody, everybody considers them nice, they seem to others as charismatic persons. But this is just a mask they have.

“she doesn't see other peoples emotions very well”. Narcissists are incapable for empathy for others, they care only for the inflated sense of their own self-importance. Women often have narcissistic traits related to their appearance but your co-worker must be a full-blown narcissist.

We avoidants have usually low self-confidence and we are easy prey to narcissists. We crave for being accepted by others and when a seemingly charismatic person pays attention to us we easily idealize her/him. Narcissists know this and take advantage of this. A seemingly “perfect” person who shows extreme liking to us should raise our red flags that we may be dealing with a narcissist.

Sometimes avoidants can be overly friendly with others (as AzulOscuro said) perhaps in an attempt to overcompensate for being socially awkward or trying too hard to be nice so that others would like them. But avoidants generally have empathy for others. This is different from how narcissists behave.