Is this kind of dog good with kids?

We have two kids, and they want us to get a dog. Some friends of ours are moving to a new city, and the apartment where they will be living doesn’t allow dogs, so they want to give us their shih tzu for the girls. Is this kind of dog good with kids? I don’t know whether we should accept it or not, and would really love some advice on the subject. Which kinds of dogs are best with kids? If we don’t take our friends’ dog we will get the girls a different dog to make it up to them.