Best wishes to you both for a complete and speedy recovery.
I am an oncology massage therapist who has worked with many breast cancer patients (all stages from 0-IV) during and after treatment. While your wife might be able to fly much sooner than this, speaking very generally, in my experience, people feel about 80% recovered about six weeks after surgery--six weeks is what most surgeons will tell you for just about any procedure. Chemo sucks, but it can shrink the size of the tumor, so surgery can be much easier. The last 20% of getting back to normal in terms of energy, range of motion, etc, can take a while--more like 6 months to a year.
One consideration no one has mentioned so far is the risk of developing lymphedema after surgery, and this will depend on whether and how many lymph nodes may be removed during the surgery. The more nodes removed, the greater the risk. Air travel does increase lymphedema risk, even though the cabin is pressurized. Wearing a compression sleeve or garment during the flight is a good idea--and your wife should definitely ask her doctors about lymphedema, and for a referral to a therapist who can perform manual lymphatic drainage therapy--a specialized type of very gentle massage that reduces edema and is actually quite pleasant and relaxing to receive.
The Society for Oncology Massage maintains a website with a locator service for finding therapists with the advanced training needed to work safely and effectively with people living with cancer, and educational information for patients and other health care providers at:
www.s4om.org.
Again, best wishes for you and your wife on your journey.
warm regards,
Martha Menard, PhD