Art Book 4 [OLD... ish]

I'm in dire need of assistance ;0

Does anybody know how to find someone who changed their user?
Because I have three people I want to find but they changed their usernames so I'm sad

These people are/were
fern_draws
KatelenePastelGoth (I think I know their new user but I forget it daMMIT)
And an irl friend: EmrysSilverheart