My yorkie, Lucy, has ripped up my tax return and likes to chew on zippers (ruined my favorite skirt and hoodie) but other than that she's pretty good. If it isn't a treat or her food it seems like she doesn't know what to do with it. A Cheerio fell on the floor and she grabbed it and then ran to her bed. A few minutes later she came out crying and I noticed it was stuck to her lip. Her little brain didn't realize she was suppose to eat it and got freaked out.
She did the same thing with a piece of cauliflower that fell on the floor. She just wants to play with it.
In response to your question about getting fixed, my friend is a vet and he said that it's easier to have her fixed on or before she is 6 months. That's what I'm planning to do.