Just a suggestion... my DD has a PEG tube and takes Jevity 1.5 by prescription. I don't see why this formula could not be taken by mouth. It is super nutrient dense... and smells vanilla-y. It is fantastic at getting my DD's weight back up. She gets 4 cans daily maintenance (but I think she's still gaining).
Does Sammie eat puddings? We had DD on special pudding product from a company in Florida, also calorie/protein dense... I'll find their info for you... they also make other products... some drinks that may help...
4WebMed
Magic cups is what we fed DD as a supplement... served in hospitals... they have a ton of products listed by medical problem...