These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Emily/Sarah is responsible for Will meeting Summer/Natasha, while Summer/Natasha is the reason Will was reunited (and later married to) with Emily/Sarah. However, none of them lead to Will meeting April, yet she is the person Will talked to before his proposal to both of them.
When Will is telling the story, it was his daughter Maya who suddenly notices April, just like the way she (April) came in to his life unexpected.
Fridge Horror: April's collection of copies of Jane Eyre with inscriptions in them. What if those books belong to people just like April? They might be searching everywhere for the book with their inscription in it because it means so much to them, but they'll never find it because April is hoarding them.
Though maybe she plans on getting rid of them after she finds her.
Heartwarming Moments: Two, when Will finds her father's book for April (though he keeps it for years) and when Will reveals to Maya that he doesn't regret his failed marriage because she resulted from it.