First of all, each dog is an individual with it’s own character and preferences, and not only genetics, but both training and life experience too can make a big impact on adult dog’s behaviour. However, when it comes to genetic part and statistics, Staffordshire bull terrier tend to be pretty good with kids (and normally counted as +1 eternal kid in the family), but selective with dogs and other animals. You can learn more about Staffordshire bull terrier temperament
here, but best is to meet different breed representatives in life.