As you only have 3 days for stay in GB and you are with family, I would say stick with one area (Hunza).. From Hunza you must travel to Khunjerab..
On your way to Hunza from Naran, don't forget to stay at Lulusar Lake and Babusar top, these are very beautiful spots..
Places to visit in Hunza are: (keeping in mind that you are with family, so less travel time daily)
Day 1 : Have free time in Hunza, visit Altit and Baltit Forts, Duiker, and for sunset, go to Eagle Nest..
Day 2 : Drive towards Khunjerab, visit Attabad Lake, Passu Cones and Sost and stay in Sost
Day 3 : Sost to Khunjerab, enjoy your time at Khunjerab, come back to Hunza in evening and stay in Hunza
You will not need Jeep for above mentioned places..