I think following plan will be feasible for you as mentioned below:
Day 1: leave Islamabad early in the morning say 6:00 am and reached at Shogran at around 2:00 pm. Take Jeep from Shogran and visit Siri Paye Meadows on the same day and stay at shogran on the way back from Siri Paye Meadows. (reason for opting Siri Paye before is that it is a hectic journey over jeep and you will definitely need a rest after that.)
Day 2: Leave Shogran at 10 am and reached Naran at 1:00 pm via Kaghan (dont have to stop at Kaghan as it is a small town) have lunch and leave for Saif Ul Malook Lake at 3:00 pm you will be back till 7 pm and Stay at Naran.
Day 3: Leave Naran and go till Babusar Top via Batakundi / Besal / Jalkhand. you will be back at Naran around 3:00 pm easily with little stop over at Lulusar and Babusar Top. have Lunch there at Naran and sight seing or river rafting.
Day 4: Left for Islamabad at around 11:00 am after having breakfast, Do lunch at abbottabad "Shaheen Shenwari" at Mesile Chowk.
I hope this will suffice for your plan.