Staffies can be very good family dogs if socialised around children and constantly supervised around young children. They were bred for ratting and dog fighting, but their handlers didn’t want a dog that would turn on them, so human aggressive dogs were usually culled. This has resulted in a breed that is very loving and friendly towards humans.
I have a staffie, she is well socialised and wants to say hello to everyone she meets and wags her tail furiously at strangers. However, I would not leave her alone with a baby or toddler. Staffies were also bred to not back down in a fight, and if a toddler were to pull her ears and make her believe she was under attack, she could be dangerous. Small babies, by the way they move and the noises they make, can trigger prey drive in dogs. Being a terrier, she has the instinct to grab hold of prey and to shake it dead. I’ve seen her do it with squeaky toys.
All dogs are predators, have prey drive, and can become defensive when threatened. Personally I wouldn’t own any breed of dog if I had a baby or toddler as it’s too much work to do the constant supervision involved.