On the first login, a child will be presented with a dialogue asking them to select a gender. Not only is the mandated choice between just two, instead of boy/girl/other, unnecessarily limiting on young minds, but, seeing as they are presented only pictures, distinguishable only by the clothing, enforces a stereotypical understanding of those two genders.
Considering that some children will undoubtedly grow to be gender-divergent, this feature seems misplaced. If it is important that the user chooses a gender, it should not be the second screen a user will see, and should instead be an option for the user to come across while exploring the system to use as they like - perhaps some extension of the journal focusing on the user as an individual.
Moreover, there should be a clear option to proceed without choosing, and/or a third, androgynous option for those children who do not wish to identify with either of the two.
I sincerely hope that developers will take these thoughts into consideration.