wow that's a lot of questions
but we've all been there.
At night it is importnat that she is in a crate that is next to your bed. Put her to bed when you go to bed and make sure she can see you. Dogs are pack animals and are used to sleeping with their "pack". Put her to bed when YOU go to bed.. it's ok if she falls asleep on the couch. when she cries just ignore her and when she is quite, quietly praise her and then go to bed. During the night if she wakes you to go out.. wait until there is a break in her crying (even for a split second) and then take her out... but at 6 months she should be almost sleeping through the night. Also her teeth will start coming out shortly.. you will probably see them around the house
her ears might go up and down while she is teething.. that is normal.
Vet bills can be pricy but when buying a dog you can expect to have to go to the vet.
you can tell her blood sugar is low becuse she will be lethargic and her gums will be white. There is no harm in giving her Karo syrup if you are "wrong" about the low blood sugar.
make sure to NEVER give her raw hide to chew on. it is horribel for her and can cause intestinal blockage. Nyalbone has something called "healthy edibles" and they are a good alternative but you NEED to be watching her while she eats these.
do not let her chew her pillow... remove it if she does and just put her to sleep on a few towels.
its ok to have lots of questions... it's scary when they are so little but you should consider buying a yorkie book! i found it very helpful!