Oh, and on the subject of Hanna's "maturity": I agree with Barbara. The show has become rather a refuge for sopranos winding down their careers, and I don't object to that, but if we're going by the libretto, her marriage to a wealthy husband must have happened when they were both relatively young. And even allowing for a decent mourning period... she surely hasn't been sitting around on their estate for 30 years before taking herself to Paris!
Another gloss which was added to the dialogue was Valencienne's bit about being curious about Maxim's and what it would be like to be a "painted woman." This gives her some excuse for taking the stage with the grisettes (she's an ambassador's wife, not a nightclub headliner). In the operetta as written, this last act takes place in Hanna's house, which she has decorated as Maxim's; Valencienne would more plausibly have her fun in those surroundings, but it's an awfully convoluted setup, and this isn't the first version to decide to just have the last act take place in the real Maxim's.