*fingers crossed on the false alarm...*
unfortunatly being in the breed for so long ive seen it all...
chis are an amazing breed, but being in the breed is both a joy and a heartbreak! even the best of breeders will loose pups, and even bitches.
in terms of diet...
a high quality puppy food (no corn no by-products) during pregnancy should provide her enough in terms of protein and fat. the way i was raised the girls got 1 fresh/organic egg scrambled (just egg no salt/butter/milk ect) with a little bit of calcium supliment. (they LOVE their eggs).