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