The shower scene that you are talking about it part of the transition scene right before the end of the current content that will lead into the next weight stage. Depending on if you swapped the statue or not you will either get skinny Jamie or Chubby Jamie. The only dedicated scene for the WG path at the moment is the one where she brings up that she has been putting on weight.
Complete the following people's quest:
1. Win all the hotdog contests.
2. Complete cici's quest of feeding her different people.
3. Help diana gain weight.
4. Give the AE/BE/Hyper serum to bakery, buffet and the black coat lady at your office respectively.
5. Unlock the fairy, feed her and she will give you fairy dust.