How and why are the McAwbres in Saint Canard?
Well, aside from Morgana and her relatives-cum-business partners, seen in “Fungus Amongus”, the family itself actually is not in St. Canard. Morgana’s parents and various other relatives actually live in Transylvania; Morgana seems to have some sort of teleportational spell in her house that transports people from St. Canard to Transylvania and the McCawber domain. As for why Morgana herself is there: well, as far as one can discern, she came to the city to break into business – even the shady sort of business she was initially involved in – and even though that failed, she returned because of her attraction to Darkwing. And of course, that has led to her family making appearances every now and again.