u/ConcentratePlus365

picture says it all. somewhere I messed up on the corner piece. can I had hot mud to the corner then add corner bead or do I have to replace?

I have a house that is 107 yrs old. currently im removing the old plaster and replacing with drywall. my main concern is on an exterior wall.this exterior wall did not have lath but only what I assume to be plaster. my question is, is this plaster? i would like to put up a 1/4 drywall to match the existing board that was there before I removed (see pics) but I’m kinda worried about moisture. there was no signs of moisture or wet spots before nor mold. can I just put the drywall up with glue to the plaster? I can’t put furring strips as the drywall will sit on top of the cabinets. any tips would be appreciated.