First of all ~ chill. Belle is going to pick up on your stress vibes so try and keep those in check (though I know it's hard when you are introducing a new puppy in the home).
Belle might take a few days to warm up to the newcomer; as I mentioned in another post, it took Ringo about a month to settle down.
Belle might go off her food today while she adjusts; perhaps you could try to give her a treat or so when you guys are alone and the new puppy is not around. Belle will adjust in her own time and her own way.
In the meantime, pay special attention to Belle. Do not pay more attention to your new puppy than you do to Belle. Give Belle everything first; your lap; your greeting; your attention; any treats; any toys, etc - Belle is first for EVERYTHING right now. Reassure her that she has not lost her status in your house.
Things will get better but it might take a little time.
__________________  Mommy to Lucy, Ringo, and Matthew |