In 20, 30, 40 years from now, 3 missed days will be minuscule! my 6 kids had more time off than that for appendicitis, hernias, fevers, tumours,chicken pox, tons of stuff! They all went to Uni, all qualified as Accountants, consultants, I.T, blah de blah….. your GS won’t even remember in 20 years, he’ll easily catch up! But bonding with brother is MASSIVELY important for his future life, bonding/ fighting/arguing/sharing. Making memories is vital for shared experiences. Shared grieving can be healing.My sons constantly talk of “ Do you remember such and such….’ Shared memories are comforting.Let him go, to love, to build better bonds, this time next year it’ll mean nothing, those that object need to “walk a mile in your shoes”. Battle on Grandma, you deserve a medal!