Oh! She is adorable! My sister adopted a beagle/chi mix and shes the smartest little thing Ive ever seen. Chihuaha's can definately be stubborn, sometimes slightly bratty but as far as I've heard, once you win their trust & love they are absolute dolls and very intellegent. I really really suggest that you crate train her, too. It seems like a crate would be a wonderful place for the shy type of dog, since, if properly trained, dogs think of their crates as their little homes or dens. Crate training would fix the destruction problem too. I'm sure she'll start doing great as soon as she begins to realize that when you're leaving you aren't abandoning her - this is usually an issue with pound puppies. Good luck with your cute little girl!