There's a rumbling cold chuckle, and then a pit fiend - the same pit fiend who was leaning over her before, as you can recognize if you've had enough dealings with devils - leans over Abrogail once more, and picks her up much as Keltham did, though with far greater Strength.
...it is possible, it is imaginable, that the lesser Carissa Sevar within Dis might have failed to negotiate any explicit compact-term along the lines of 'When I use my Gate back, the pit fiends are not allowed to follow me, invisibly or otherwise.' It is not the sort of thing you'd imagine a pit fiend to bother doing, if it wasn't an effortless cruel-prank to play while you were right there. Or the lesser Carissa might imaginably have thought - especially if she feared her own true loyalties - that a faithful subject of Asmodeus ought not want to impede a pit fiend, if something mattered that much to Hell's third tier of nobility.
Hell does like its little games, you could say, especially when it comes to granting Wishes that are the least bit interesting.