Friend can't adopt villager

[PinkCrayon]

I'm trying to give a villager to my friend but here's what happened

Friend asks villager to move in > villager says her town is full > friend goes back to island and opens a plot > asks again > villager still saying her town is full

Has anyone else had this glitch?
Is there any known fix or is she just screwed?

Edit: also the villager moved in and out naturally

 

[cheezu]

Does your friend have an open plot that's unclaimed by anyone else or is their current villager still in boxes?

 

[PinkCrayon]

Does your friend have an open plot that's unclaimed by anyone else or is their current villager still in boxes?

Apparently she went on a tour and invited another villager, and thought having full plots would let her kick another villager out when she adopted mine, so we found the problem