
Some of mine would have 'morning sickness', others didn't. Take my advice (

) and leave her diet as it always is, maybe cutting back on the bulk towards the end of her pregnancy when she won't have as much room for food. Like us, there's absolutely no need to be getting her fat and make for complications with whelping. In the wild, bitches would remain lean after all, as we should. The pups will take when they need from her and it's really only necessary to adjust her diet once you know how many puppies survive through whelping. Again if she only has a few she won't need much more food - if she has a lot to cater for, THEN you adjust by upping the amount she has to eat.
We had our bitches wormed and boosters brought up to date before the mating, and they were on a good quality diet throughout, so no adjustment was ever needed. Their puppies were usually a good size, even litter, maybe even bigger than some of my breed at birth.
I don't regard Royal Canin as a good quality food, and all this breed-specific food is only a sales- ploy. You'll find the make-up is the same, even if size of the kibble differs, small for small breeds, and larger for bigger breeds.