If your wife is suffering from depression or even just feeling under pressure from your child's disability i would definitely recommend that you help her get counseling or therapy prior to tackling the weight issue.
Above all i would not give her DNP. I suffer from PTSD and when I have used it when I wasn't in a good place and it put me a lot further down the hole than i had ever gone before. Sure your wife may loose some weight but it wouldn't be worth it if she was in a crapper place mentally.
There is no quick fix for this and you'll have to support her day by day. What Hogan86 said about getting a solid routine in place is totally correct, but from the sounds of things your wife may not be in the right headspace to see this as a possibility at the moment.
Above all i would not give her DNP. I suffer from PTSD and when I have used it when I wasn't in a good place and it put me a lot further down the hole than i had ever gone before. Sure your wife may loose some weight but it wouldn't be worth it if she was in a crapper place mentally.
There is no quick fix for this and you'll have to support her day by day. What Hogan86 said about getting a solid routine in place is totally correct, but from the sounds of things your wife may not be in the right headspace to see this as a possibility at the moment.