I like to think that she wanted to go to the ball because she was tired of being defined by her job scope. I mean what she did was even in her name -- Cinderella from the cinders that smudged her face from cooking all day. Cinderella the maid. Cinderella the cook. So she went to the ball to regain that sense of identity and she was ever grateful to her fairy godma for the dress and glass slippers because the fairy saw that Cinderella was just a girl and girls no matter how tired, like pretty things. And this is also true of boys, but I'm not going there.
And I like to think that when she went to the ball she didn't know it was the Prince but he was hot and the strange blushy reaction she got when she saw him didn't really confuse her because it just reaffirmed that she was human and it was right and natural to feel all these things. And she didn't know what to say when she danced with him, so she offered him a recipe for stew and told him a secret (barley grain made stew taste even better) and the Prince was amused, and they weren't in love with each other. Yet. And when the clock struck midnight and he offered to kiss her, she politely declined because she didn't know him all that well, except that he had been very kind and listened to her. Then she ran off.
And when she went back to her old tired life, she was sad but glad because she knew that she was alive and human after all. Except sometimes she worried about him because he didn't have barley grain in his stew. And the Prince went back to his clean well-ordered life but he thought often of the girl who had been so obviously not been of the nobility. And he might have smiled at the memory of her from time to time when he was alone. Until one day he realised that he was in love with the memory of her and he needed to rectify that. So he brought out the shoe and went searching. And I like to think that the glass slipper was just a metaphor for how fragile appearances can be, that we shouldn't take things at their face value, because when he finally found her, she was covered in muck and grime but he recognised her anyway. And she wasn't proud of her appearance but she wasn't ashamed either because it was only a necessary result of all the work she'd been doing.
And I like to think that the Prince realised how wrong he was to have fallen in love with the memory of her because the real woman was so fully present and alive, incomparable to his flimsy memories.
And she, she was glad because he had recognized her. And that was how they fell in love. Only after all the hard work. Oh there was more hardship later on in their lives, but I like to think that at that re-encounter they fell in love because they knew that neither of them was afraid to work to get what they wanted.