Frankly, she is in a terrible place, and
a lot of suffering, determination, and
support is, and
will be, in the future to get her completely off methadone.
You both should learn, make decisions, formulate a plan, including aftercare, and execute the plan. Sounds easy, but it is not. The first step is knowledge. That, knowledge, is my best advice.
Sorry no-one has replied to your post yet, but believe me, thare are many. many wonderful people on here who care and will help.