^Also I've been lurking on this thread for a while now, and someone mentioned how Dany has never taken a good guy for a lover.
Khal Drogo and Daario may look like puppies next to Euron, but they do and condone some pretty terrible stuff themselves.
Couple that with Euron outright lying to Dany + using his charisma, he's going to get her on board for sure.
I don't think the woman in white is symbolic of Dany though, I think she'll ditch him after coming to Westeros and/or learning what he truly is. I rather like the theory about her being symbolic of the Others. Cersei has always been referenced with green so I don't think it's her, but I spose she isn't off the table. Val has always been white but I don't think that quite fits either.