Game of Thrones history has suggested that, on balance, what Daenerys wants, Daenerys gets: dragons, an army of slaves to free, control over Meereen and a feasible claim on the Iron Throne.
So when it comes to a small case of curing a doomed, enamoured faithful servant such as Jorah Mormont of a life-threatening disease, that's child's play.
In Season 6 we saw Jorah, the oldest love-struck puppy around, sent around the world on a medical gap year to cure his swiftly advancing greyscale: a disease that turns its sufferer's skin hard and stone-like, eventually driving them mad.
In a world reliant on ravens - metaphorical ones embedded in trees, as well as the usual avian kind - for communication, this seems like quite the challenge.