Before heading to find the others and with the kids following them, Logan thought it would be best if they found and cleared their escape route first. They decided to head to the beach where the platform with the spaceships were. Once this was cleared, one of them could stay behind with the kids and continue the search for Quinn and Vorden.
Ideally, Logan was hoping that when they arrived Quinn and Vorden would be there already waiting for them. When they started to get close they slowed down, Pam Wight was sent out instead.
The beach was expected to be guarded somewhat as it was one of the more obvious escape routes. Sending Pam was clearly a decoy. If anyone saw her they should recognise her and ask questions before attacking.
Even though the Wights weren't cable of speech, this would be enough just to get the surprise attack on them. However after searching the beach for a little while, Pam returned shaking her head, claiming that there was no one out on the beach.