When the boys first see Wendy, they think she is a bird. Then they shoot her, because Tinkerbell tells them too.
When Nibs sees her, he calls out.
"I have seen a wonderfuller thing," he cried, as they gathered round him eagerly. "A great white bird. It is flying this way." (ch 5)
Unfortunately, Tinkerbell the fairy sees Wendy as a threat. She tries to pinch her, and then tells the boys to shoot her.
It was not in their nature to question when Peter ordered. "Let us do what Peter wishes!" cried the simple boys. "Quick, bows and arrows!" (ch 5)
When she lands, they realize that she is not a bird, but a lady. They feel terribly, because they think that Peter brought them a lady to take care of them, and they killed her. Tootles even starts to run away, afraid of what Peter will do.
When Peter arrives, the boys crowd around Wendy to hide her. Peter is confused because they don’t cheer. They try to cheer, but they can’t. When he sees Wendy, he asks who did it. Tootles confesses, and Peter starts to stab him with the arrow. Then they realize she is alive, because Peter kissed her and made her better.
The Lost Boys' reaction to Wendy's appearance demonstrates how they are both childish and savage. They do not necessarily mean to hurt her, but they also do not question Tink's version of Peter's orders, and seem more interested in being punished by Peter, or perhaps losing the services of a lady to care for them, than feeling sad about killing someone.