In reply to Busby:
Southeast Ridge (AD 4c) - about VS, fantastic summit and 15 mins walk from the lift, makes for a great half day.
Alternatively, on the same bit of rock there's Brunat-Perroux (D+ 5c) - technically harder, but with a smattering of bolts too.
Clocher cochertons traverse (AD 5a) is fantastic, if a little short. Cocher Cochon (TD- 6a) is harder but fully bolted and also superb and finishes on the summit that the traverse starts.
If you/her are properly acclimatised and up for it, Rébuffat-Baquet (TD+ 6a) is the big classic on the SF of the Midi. Arête des Papillons (AD-) is the classic of the Plan.
And I know you said you'd prefer trad to sport, but "Les Chesereys" slabs just above Argentiere has some great ~150-200m multipitch sport routes with lovely views and no lift required. Also lots of curious Ibex!
Post edited at 15:59