Hi Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concern...
You can take your wife to trip, If your physician permit it after doing her checkup & take care of following precautions
1. Altitude acclimatization- Altitude acclimatization is the process of adjusting to decreasing
oxygen levels at higher elevations, in order to avoid
altitude sickness. Once at 3,000 metres (10,000 ft) stay overnight or few days there & then go to a higher altitude (slowly).
2.The drug
acetazolamide ( Diamox) should be available for altitude sickness. Acetazolamide can be taken before symptoms appear as a preventive measure at a dose of 125 mg twice daily.
3. Never try to over exert yourself & specially herself
4. In case of any problem decend to lower height
Hope this information helps
thanks & regards
Dr vivek goyal