Susan was glad that Hannah was doing this for a number of reasons. It was always nice to see her friend, but additionally, Susan felt a strong camaraderie with the DA members because of what time in her life she was taken. It was also nice to go out to a social event that wasn't spending time with her aunts and uncle. She adored them and the chance to get to know them here but it would be really nice to spend time with people closer to her own age.
It felt a little strange having to ring the doorbell when she was so well acquainted with number 14, but Susan wasn't crashing on the couch anymore so she figured it was polite enough not to barge in.