[concretegurl]

What's a Shorkie? I'm not familiar with that mix, is it a Shih Tzu Yorkie mix-breed wise Shih Tzu are very good with children Yorkies not so much...

Aggression by a dog is unacceptable especially with children around.

First you need to ensure your children are properly dog trained.

Second the dog needs to be properly trained without any aggression toward it or over-stimulation which can result in more aggression.

Does the dog take treats from the kids-who has dog bitten?

What was going on surrounding the biting incidents?

Drawling blood means the bites aren't a back off nip it's a full on I will bite you to make you go away from me...

Since this has reached this level already you need a dramatic intervention to absolutely separate this dog from your children and make sure the children leave the dog alone and you yourself need to do the training or re-homing.