This game is not meant to be completed (Gallery-wise) in a single playthrough, it is simply impossible.please do, it seems very odd how only 2 trip companions don't have events unless already in a relationship with ainz. (even more so if you mentioned to solution you wanted to have sex with her but didn't on day 160 due to ring limit)
actually speaking of, think you could consider scripting a suspicious door event to that day? that would also solve the 4+ preg/relationship start offs with only 3 charges issue. i only got that event on that day once so far and it seems pretty unfair to rely on RNG for something like this.
The Suspicious door appears randomly in the world, the only scripted thing is that it will appear every 7 days depending on your last visit and the amount of total events.