Phew! I deeply apologise for taking so long to make this post.
The girl in episode 6 is named Liliruca Arde, or Lilly for short, and she serves as Bell's main supporter while he travels in dungeons. She has plenty of secrets surrounding her.
With most of the screen time focusing on Bell going throygh dungeons and fighting Hestia hasn't had much to time to shine lately. Next episode seems promising for a lot of content.
As always, thanks for reading!