Rules FAQ pt 1

It is possible to wind up with a character that is both in play and in the dead pile. This has no effect on the character currently in play; there is nothing in the rules that prevents this situation. The rules on dead piles/uniques are quite explicit; having a copy in play simply prevents you from playing/putting into play/taking control of further copies. This does have the following practical application: you can no longer place a duplicate on your living copy of the card, as marshalling/putting into play a copy of the card is prevented by the presence of a copy in your dead pile

Rules FAQ pt 2

Crone of Vaes Dothrak can react any time a character is discarded from an opponent's hand or deck. For example, during challenge resolution she could react to The Reader in step D of DUCK, react to intrigue claim in step C, or react to Pillage in step K