Well donkeys are so very easy keepers unlike some mini horses that if this baby is in real good shape and plump for the up coming winter she may not need to have any grain at all As lonmg as she is eating grass and hay, there is sufficient nutients in just that. I know I got my first donk at 4 months of age and would only give a "handfull" of grain and that was really just for a treat..Donks take so little food to live on because of the way they were bred...Living in mostly with very little vegetation..I know it is hard to see a baby not wanting to eat grain but do this put a small flake of hay on the ground sprinkle some grain on top of the hay and see if she will at least nibble on some of the grain as she eats the hay, Just a thought..
I know on the donkey boards many people say only feed grass hay to donkeys no alfalfa or even alfalfa mixed hay, donkeys just6y don't need that kind of protein,,, But i have been feeding mine a mix of about 30% alfalfa mixed with grain but just so little a flake that one can barily feel the wieght of the flake when carrying it...