My child fixates strongly on one particular friend.

Turning strongly toward a favorite person is also a sign that a secure relationship has formed. However, if wanting to monopolize them, becoming anxious when apart, or the other child feeling burdened continues, the relationship can become hard to sustain. First accept your child's wish to be together, then ease the pressure by (1) gradually adding other people and activities they can enjoy, (2) showing a plan such as "today is a different-play day," and (3) conveying with short words and pictures that the other child has their own circumstances. Sharing a comfortable sense of distance with the other parent and the teacher also helps.