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.
YMMV: Step By Step
Fridge Logic: Lily Foster-Lambert receiving her mother's late former husband's surname.
It actually makes sense. This was a nice way to resolve a series premise. It symbolizes the successful union of the Fosters and Lamberts as a family, bringing the related plot lines to an end.