The woman in red was no friend. The way she spoke about Martin was disgusting. (I'm paraphrasing here but the gist is obvious) "We thought she'd get with someone gorgeous, hunky, successful, black etc etc but looks weren't important to Joyce. We were shocked to meet Martin..." She must have known he'd watch it too? 
I was saddened when the party thrown for her 21st consisted of Martin's friends. People she didn't really know.
I know the girl who played Joyce. She was my sister's housemate at uni in Manchester. Stunning girl.