Bubbles is the last to be introduced member of Pumpkin's trio of friends (Ashliii is the second, and was introduced as one of Ellie's co-workers at O'Jacks).
We haven't seen a lot of Bubbles yet. First appearance was in comic The Less You Know. It was also mentioned that she works at a drive-in.
We see her first name is actually Bethany and her last or middle name starts with "An" on Pumpkin's social media friend list here.
So far she appears to be the passive member of the trio with Pumpkin or Ashliii more likely to take the lead, but this may just be due to lack of time seeing her so far.