I would recommend a trio of birds, beginner’s breeds like the decorative Pekin, that come in many colours, so that each member of even the largest family could have their own different coloured bird to care for. They are docile and patient.
Alternatively, try Silkies, Dutch or Belgian bantams or the massive Orpingtons or Brahmas. If you have a large garden, why not give a home to a few commercial hybrids or re-homed battery survivors? They also lay far more than the pure breeds (try the Battery Hen Welfare Trust
www.bhwt.org.uk). Cockerels are not a good idea, a large cock bird, however docile, can frighten small children and put them off chickens forever.