Her ark did nothing to Mael (or Estarossa) because it was non-lethal.
She only intended to displace him, there was no intention or an attempt to hurt him.
The only hint that maybe Elizabeth's ark should've hurt Estarossa is through the AA's comment, but considering how they only saw him escape the ark, and not witness the entire situation, means their comment isn't that credit worthy.
As for the AM slap. I believe Elizabeth does have the power to hurt Meliodas, but it would never work in battle because he would just outspeed her, dodge it, block it even, or full counter.
But still, a weakened Elizabeth minimally hurting a 142k passive demon is something to consider before you go ''lol 30k Elizabeth''.
You mean how Derriere ''cheap shotted Elizabeth''?
But yet everyone is quick to agree with that feat and acknowledge it as proof of Elizabeth being ''weak''.
Stop with the exceptions