I just saw Merana and did her quest. I think I pinged the group correctly but I am not sure. What is the best way to make sure I did?

A successful ping will link to that group's main page so you can just check that.

For example → it's just a random hashtag → link that directs me to this group's page

(Btw, it did go through, I got the ping ;))

okay good! I had no idea what I was doing so I was copying what i saw above (I just asked yesterday and joined the group) and low and behold she made an appearance!