I question this also. I don't believe she wouldn't go over and say hello or ask anyone who they were (if she really didn't know the men), unless she had reason not to. For example if she and CL weren't speaking or the relationship between them was strained in some way, or maybe she knew something was brewing and wanted to distance herself, keep herself out of the firing line.
If your close friend was in the pub, had been drinking all day, you noticed enough to say she was 'plastered' and sat with a group of people you didn't know (and therefore possibly CL didn't know either), wouldn't you go over and say hello? Ask others in the pub who they were?