depending on your state and her income, there are weatherizing programs that might help. But that might be just a california thing with PG&E funding it. If the home has aluminum frames, you might want to get vinyl inserts. We had home depot do a duplex we had before we sold it.

The labor seems really high. But if they are busting out the old frames and repairing the damage to the exterior, then it might justify that. For a 2 homes we did, we just bought the inserts from home depot and had them delivered. We have access to friends who do construction so our install costs were far less.