In my experience halfway houses can be a great asset or another enabler. Here is why,,,a good halfway house will have drug tests, meetings, and rules. You will know by talking with the people who run the facility and asking questions about the house and it's rules and if there are AA or NarAnon Meetings etc. Now, you can also find other halfway houses that are no more than a boarding house for addicts which in my opionion can quicky lead to relapse.
I was in many halfway houses years ago when my boyfriend of 3 years was trying to get off opiates so I do have experience with them...In fact, for one year i was in and out of many of them visiting him. My best advice would be too find a good halfway house and let her go there for awile till she stablizes in her recovery before jumping back into living together.
For the record my boyfriend never lasted long at any of them. He would either find a buddy in the house and they would go out and use together and not return...or he would use drugs go back to the house be drug tested and then they would kick him out. Of course, he wasn't serious about being sober so anywhere you put him he relapsed. I do believe though if your wife is committed to recovery and she is in a good halfway house she will do well. Many of my ex's friends really sobered up and got their acts together by staying there and stabilizing in their recovery before returning home.