that option should have come up when they announced the first pregnancy, they would start talking about needing more space and where they are getting the money, eventually they will ask for a loan, when you give them it they start the house upgradesThat option never popped up, however, the day timer stated counted up finally!
I think maybe because I had sex with her multiple times in her new birthday presant outfit.
[I'm pretty sure I did that a few times already, but here I am...]
Probably the since the “Intervention” quest wasn't progressing and Jenny was stuck on "Day 4" I thought it was bugged.
Maybe there is some other requirement not mentioned, but I'm hopeful more sex solved it, haha.