Reading the previous thread, Mandy originally didn't know what to think of you. She noticed that you were awkward and was trying to make you feel comfortable, but did not know how to do so without pitying you or making you feel different. This made you feel hurt and confused by her behavior.
When you saw her at this party, she may have realized that she hurt you (as evidenced by her saying sorry, a bunch of times) and was trying to make things up to you with an gesture of friendliness (a hug). Since it was an over the top gesture, there's a chance she is still pitying/babying you. As you were feeling hurt by her actions, it would have been a good idea to say hi at least but politely decline the hug as it would lead to more babying types of behaviors by her, which you don't want.
I'm not going to pass any moral judgments on her behavior because I believe that people are capable of change and should not be shamed for behaviors that they are capable of changing.