You are now promoted to administrator for the Welcome group. Thank you for doing that! It's as little or as much as you make of it.
Feel free to make any changes you like in the options, group page, group info, etc. I think just about the only difference between administrator and creator is creator can designate administrators and has their photo on the group page.
I had also emailed Ruth with the same message. My thought is since she also welcomes new members, it would be appropriate to have both of you in that role. She hasn't responded yet, so we'll see.