I don't know from where you will be travelling....
I started my travel via deawo from Lahore at 11PM and reached Mingora at 8:30 next day. From there I took a Hiace to Sakhra, from Sakhra I took a car ride to Lalkoo Bridge.
I was there by 11:30.
After waiting for sometime and failing to find a porter,I set on the trek at aroun 12:00 PM.
I reached at GaBina Jabba, at 6:PM. My plan was to go to Darral next day, but I could not find any guide or make any local to go with me. People don't speak Urdu there. There are a few very distant shepherds in Gabina Jabba and none of them speaks Urdu. Lucky for me there was a school trip there, they translated for me.
If you can find a guide, or a local who can go with you, I think you can do it in two days. you might need to camp at Lake for a night depending on how good of a trekker you are.