Your wife will be fine.
I would suggest a few weeks in Jak, then get out and about around SEA – go see some orang-outangs, go to Thailand, and get off the tourist route and explore North East Thailand, really get into it. I travelled by locak bus and trains all around the North East when I first went, just hoping on buses and seeing where they went.
From North East THailand head into Laos, up to the North, work her way back down to the south back in to Thailand and a train to BKK and into Jak for your return.
I saw some wierd and wonderful things out in the villages and towns. Met some really nice people and had a laugh, but did it all on my own.
Spent three weeks at one point not speaking to anybody in English, just having to muddle by on phrase book Thai.