Well she's one of the three (well four if we count Volo, ok five if we put in the Goblin piestress) possible solutions to the tadpole problem, Haslin will give you some hints, Auntie Ethel the same, of the thre primary possible problem solvers only the Créche remains (at least in my playthrough) without "succes" [that is: where in all the frozen hells of all the pantheons is located? Do they decide to put this part in the full release? ]

Furthermore:
There's a mail traffic between Ethel and somekind of recruiter of victims in Baldur's Gate, we also know that someone in the city started an investigation and was pursuing the hag, moreover some her unwilling guest are directed to BG, one with the clear purpose of hunting down the hag's contact.

Last but not least what you choose about Connor's fate is one of the point that shows more clearly the alignment of the your main character : lawful, maybe neutral too, good will destroy the wand, a chaotic neutral will give Maryne the control of Connor, thus opening a posible further development because she decided to travel to Baldur's Gate, a neutral evil and chaotic evil will give her some hope resurrecting Connor and then crush her killig him, a lawful evil will resurrect the dead husband and maintain him as cannon meat.