Hi Dave,
I used to work in home loans as well so I can offer some insight into this. In regards to this, although you do have the option to essentially "partner" with some other family members. Quite frankly I would advise against it. Even though both yourself and your wife have excellent qualifying criteria, often times they took a look at a whole of who will be owning the property unless you will be paying cash.
Since some of your family members aren't exactly in the best situation, it might be good to speak with someone with knowledge in real estate as well as in the mortgage industry that would help look further into their background.
Was your purpose to solely be helping them get a leg up or were you also looking to invest in real estate alongside with them?
If you like we can speak further and maybe give you some further insight into what you may be looking for and what you and your family are trying to accomplish.