I am already scheduled for an interview outside the U.S. I am on an H-1B visa and will apply abroad.

My wife is on an H-4 visa, and because of a scheduled surgery she cannot travel with me. Her doctors are advising against that. Her visa is derivative from mine, as I am the principal.

Can she make adjustment of status here while I do Consular Processing? Or should I change my application from Consular Processing to Adjustment of status so that both can get our visas?

If I go Adjustment of status, it could take q to 2 years. If I go Consular processing, I could be done by october.

Any ideas?

Your wife can file I-485 after your obtain your GC via CP. Or she can go for the CP interview at a later date.