More and more children have already socially transitioned – often including pronoun changes – by the time they present to gender clinics.
Dutch data  indicate that, between 2000 and 2004, 3.3% of children had completely socially transitioned (clothing, hairstyle, change of name, and use of pronouns) when they were referred to gender clinics, with 19% already living in the preferred gender role in clothing style and hairstyle, but not announcing that they wanted a name and pronoun change.
However, between 2005 and 2009, these percentages increased to 8.9% and 33.3% respectively, demonstrating that social transition is becoming more common before medical transition is investigated.
 Steensma, T.D. & Cohen-Kettenis, P.T. (2011). Gender Transitioning before Puberty? Archives of Sexual Behavior 40 (4): 649-50. [Link]