The point that TSoL made goes even deeper than simply what a boy in socially encouraged to play with and what a girl is. Even the speech patterns and games all reinforce the socially accepted gender norms. Boys are encouraged to play games where there is a clear winner and a loser. Girls play games that encourage a victory for everyone. A woman who expresses male speech patterns is called a bitch, while a man with female speech patterns is called a sissy. In reality though, someone who is able to use both a male and female speech pattern will be better adapted to succeed. Because in male speech pattern it is insulting to try and mirror a situation (eg if I was in that situation I would have done this and that) while that is what is expected in many situations with a female speech pattern.

To see if a specific gender is inclined to any specific habits, you need to take a few hundred children, isolate them from all contact with humanity, and present them with several random "boy", "girl", and "gender neutral" objects. This is also going to cause these children to be socially inept, and damage them beyond repair as a child needs contact with other humans to develop language skills from a very early age, or the ability to learn language will be lost. (This is referring to the child's first language) so the ethics of such an experiment make it impossible to actually do.

Freyas niece was most likely exposed to some message that conveys girls like flowers. Most likely through a visual exposure through TV, or watching her mother enjoying flowers.

either that or the first time she brought flowers, there was a positive reaction and that positive reaction taught her that flowers make Mommy happy, so I should bring more flowers to make Mommy even happier.

For those with attention deficiency disorders, here is a summarized snippet of the general ramblings for you to ponder over - Gender roles are ingrained everywhere in culture. You can only see if there are true gender differences in behavior by using experiments that will severly damage many children. Have a nice day