Welcome. Your pup is adorable.
If you want her to eat hard food thats all you should give her. She might refuse to eat for a meal or two, but she'll get over this quickly when she realizes you aren't going to coddle her. If you have a set food schedule and only put the dish out for twenty minutes she'll develope a habit of eating the meals you give her right away. Dont give her many treats until she starts to eat her food consistently. Yorkies tend to have dental issues so hard foods are best. What brand are you giving her?
I think your pup would be better off at home than going to the mall with you. Soialization is good, but a crowded mall is a bit much at first. I personally don't like carrying cases, dogs should learn to walk rather than being carted everywhere. Does your mall allow dogs?