Thank you for the outside confirmation of some things I already suspected were important (specifically "wedding bells" and the importance of building up Penelope's confidence over the course of the game)!
Also, a general tip - when the game gives you a choice between interacting with people and being alone, it's usually better to interact with people at least until you figure out which interactions your build can be successful at and which ones they can't
This applies to dates (which generally give either +10 to one skill, +10 to knowledge or +5 to two skills) but also stuff like throwing events! What people think of you is important!