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.
Momoko is surprisingly good at Pachinko despite her protests at the game (a nod to her seedy roots?), has a far better relationship with her grandma than either of her parents (or anyone else for that matter, Ichigo notwithstanding), and is shown to be just as much of a fighter as the rest of her family with a temper to match at the end of the story where she saves Ichigo from the other biker gangs.
The manga is heavy enough on it, what with how the cover has them standing so close, Ichigo is mistaken for Momoko's boyfriend by her father, all the things they do for each other, and of course, at the end, with (Momoko resting her head on Ichigo's back and blushing, whispering, "I really like you, Ichigo!") The last line of the novel is "Feeling the wind against me I softly laid my head against Ichigo's back, the way I might with a lover." Take that as you will.