Given that you are puting this together from scratch, I would definitively recommend a wholistic approach: Explore combinations of speakers and receivers that are likely to work well together. As many of us know by experience, speakers can sound very different based on the other components in the system. If she does not like the idea of separates and wants a receiver, I would recommend something like a used Linn Classik matched with a relatively high efficiency speakers, like, for example, used Triangle floorstanders.
Good luck!
Good luck!