My yorkie is going to be two in April and she doesn't know ANY tricks or anything. She was not taught anything as a pup and therefore doesn't know what even SIT means. I've had her for about three months now and I would like to teach her at least some basic commands like sit, stay and shake a paw. She knows NO because if she is going for the garbage and I say " Stormy, NO " she will stop right away and back off. I try with a treat to get her to sit but Idon't want to hurt her and she doesn't just sit down. I know before she was very bone and barelly had a "butt" so I didn't know if it was uncomfortable for her to sit or what. Now that I have put some meat on her she has a little butt and does sit on her own sometimes but never when I ask. Is she too old to learn?