She does this in every episode...

or.... Maybe the writers are conscious about her characters boobs. She clearly is not

You really think the director literally tells her to do that because its part of the character?

Ya Mama.

Judging from all the photos she plasters all over the interwebz, she is clearly not worried about her bewbs. Of course, they still dress her like a conservative good-girl as it is supposed to be "somewhat" of a family show. They have been hiding her chest in sweaters and baggy clothes for quite a while until it was impossible. I don't see it as much of a stretch that they told her to try and not display her cannons.

is it realistic anymore for nerd girls to be as awkward and conservatively dressed as Alex? Considering that it's not the "Revenge Of The Nerds" 80's anymore and it's actually become cool to be a "nerd". Girls are into Game Of Thrones and stuff and dressing up in sexy cosplay outfits. You really didn't see this 20 years ago.