You can have the exact same draw length, shoot the same arrows, have the same peep height and anchor point...and it would be very rare for the two of you to shoot the same.
Women tend to use their back at anchor more than men, they have unique issues with string contact in the chest region, they have different facial features that can effect string pressures and most women get their hand into the grip a bit more than a man does. This all effects the shot.
I do shoot the wife's bow often. It's quite a bit of fun! And I have killed a few animals with her bows. But I can neither set her sights nor shoot spots with her sight settings. If I want to shoot it well I have to shoot it instinctively ignoring the sight and the peep.
Personally I'd rather see you buy two properly fitting bows in the modern economy class than see you try and make one high end bow work for you both. Todays economy bows like Bear's "Wild & Prowess" or PSE's "Stinger X & Brute Force Lite" are actually really good shooting bows. And much easier to shoot well than most of the $1,000 bows on the market today.
IMO - Get her what she needs to shoot well and enjoy the experience of husband/wife shoots. She will appreciate it more, have more fun and likely take to the sport with more enthusiasm.
