You do know she is double pregnant right. She has another child on the way from the mc.MoonBox, Sorry for throwing something of a nitpicky question but - how much time has passed ingame since Tanya's baby was born? No medic or father to really keep track, but i think it usually takes between 2-6 weeks for a woman to (mostly, mothers gaining weight through pregnancy is far from uncommon) recover her before-pregnancy form.
Would really like to see Tanya close to what she was when the MC first boinked her.