How do you cure Dog Depression?

it's like when a new baby comes, the 'older sibling' will always feel a bit rejected. from my experience what dogs love most if affection and care, so as long as you still feed it, give it walks and every so often a rub on the belly, i think she'd be okay. perhaps when the puppy gets a bit older and they can play properly together they'll grow. why don't you try taking her to a dog park, teach her how to be around other dogs?