OP are you in Hampshire? My school's head said that Hampshire County Council trained all the Hampshire schools with the No Outsiders programme, and this book was included in it. My DD (year 6) had this book read to her, and she (independently of me) thought it was incredibly sexist and weird ('girl's clothes', 'girl's things', girls are pretty, girl's dance, 'girly dresses'). Her (male) friend could not understand why they were having a weird pre-school book read to them when they are 10-11.
No Outsiders have totally drank the KoolAid, and push trans ideology and dogma in schools, and make you feel like you are 'not inclusive' and 'mean' if you question this illogical and cultish faith-based queer theory ideology. Here is one of the No Outsiders trans lesson plans, promoting bizarre, postmodern, queer theory about 'gender identity': equalitiesplans.blogspot.com/2015/10/transgender-equality-are-you-boy-or-are.html
No Outsiders are totally dodgy - pushing dogma and sexism, masquerading as 'inclusivity'.
I was furious as schools are supposed to consult and inform parents about SRE (sex and relationships education), yet this bizarre book was read to my DD's class with no warning to parents.