K.P.
You don't need "all the information" about his condition. You need to know the information regarding child support. If your daughter would like to know how her father is doing, at 13 she can call her step mother and find out.
You need to contact an attorney to find out how to go about this. If the CS was auto deducted, then it will likely be auto-deducted from the disability check, but be aware that with a reduced income the amount may change.
When he is out of the hospital and in the rehab center, I would suggest that YOU go out and see him with his new wife and ask about revisiting the custody agreement in light of the new circumstances. Until the doctors have an approximation of his recovery, you really shouldn't make any changes to the visitation- just make sure that the CS is back in place.
This is all VERY new, so bringing it up before he is released for rehab care would be in very poor taste (unless you are unable to provide for your daughter without it).