Why is my dog so sad now that i have a new dog?

hey i have a dog and my lil bro just got a new 1, and i know that dogs get sad when a new puppy comes around because every 1 pays more attention 2 the new dog. so i have been paying like WAAAAAAAAYYY more attention 2 my dog, but she is still sooooooooooooooo upset that she is just ignoring me and not acting the same as she was. she was a playful lil yorkie that EVERY1 luved but now she is acting like she has no purpose in life. im really upset about this and im wondering why she is acting in such a foul mood, could sum1 tell me why she is acting like this, could it be the type of dog she is, could it be normal, idk i just really need an answer fast!