I fostered a kitten that was deathly afraid of dogs, she would turn into a furry ball of claws. Honestly, I just let her out after showing her where to potty and a place she could hide away from the other creatures. After about a week she would let Rizzo play with her
Just don't let the two puppies gang up on her, it'll be too much. I'd say let her go mess with the one that doesn't seem to interested, then introduce her to the rambunctious one.