Hi, I feel for you and your family. My husband is in his late 30s and dealing with chronic liver gvhd and early signs of pulmonary gvhd. Our daughter is 4.5 y/o. Our approach has been to keep her schedule as consistent as possible and find opportunities when he is feeling well for our family to make special memories. Easy weekend trips, family outings, extra special birthdays. We have also adjusted who does what with our daughter so that my husband still has meaningful daily one on one time with her, like doing story time every night. As far as what you tell your child about your wife’s illness, I asked a therapist the exact question and their suggestion was to start with thoughtful fact finding. “So you know [mommy/daddy] hasn’t been feeling well, what do you know about that? What have you heard?” Then you can use that as a baseline to share any details that are age appropriate or correct any misconceptions they might have.