Kaido and Mom could probably survive in lava if they were healthy and conscious but in their current states I don't see how they get out of the lava and if they do get out there's quite literally no possible way they would be in fighting shape. How would they even breathe? It's not like they can haki up to defend themselves while they're K.O'd. Do you think they can just straight up drink and suck magma down their nose?
This is how she looks in the chapter confirmed.