You can find the way to get the extended gym scene in the game's walkthrough!
I tried it and went through it day by day, thanks for the link by the way but still am struggling a lot to get the extended scene, any advice or information on if there's something's specific about the choices I make. because I keep on doing the most feminine making transformations, and visited aurora multiple times before the princess scene but each time it doesn't give me the breast transformation until gym. is this a glitch or something I'm missing?