Congratulations on your wedding. May you have a blessed married life.
Daewoo Bus goes from Pindi to Murree. Make sure you reach pindi by the time when Another daewoo is ready to go to Murree. That way you can switch buses at daewoo stop and go directly to murree. (If Islamabad & Pindi are not part of the trip). For Honey Moon, Nathiagali is a much better place than Murree (1.5 hours distance from Murree). It is very peaceful, Green and beautiful. You could enjoy the serenity and go for treks on Pipeline track, Mushkpuri track etc. A Number of coasters go to Nathiagali from Murree so transport wont be an issue. You can spend a night in Murree and take rest. A walk down the mall road. And leave for nathiagali the next morning.
Hotels are not a problem. there are a lot of good hotels in both Murree and Nathiagali.