She is desperate to achieve something specific, but she feels she does not have the power to do it. That's why she made a pact with something that made contact in her dreams. So her desperation triggered the patron to contact her and offer a deal. Power she needed for service.

The thing she wants is something personal, and something that seems impossible by mundane measures.

A younger sibling who disappeared in the sinister swamp? Or forest? Or mines? They might have been kidnapped, or just wandered off seeking 'adventure'.