At 11 and 14, it is okay to INSIST that the kids take on some of the responsibilities - they are part of the family, and must contribute as such. Simply tell them what they must do, remind them that they are part of the family. If they refuse, remove privileges.
As the patient, I greatly appreciate all that my husband has done for me as caregiver, but I want him to have his own life as well. Fortunately, at least for the time being (and hopefully forever) his caregiver responsibilities are done, and I'm doing great.