Alexis doesn't like you because you're Joker's kid. Of course you take so much of Joker's desired attention away from her, although he usually pays attention only to himself, it is not surprising that she treats you like a helpless kitten. What is it like to be Joker's kid? Well, it's clearly not a joy, because your father doesn't care where you are, who you are, what you are, and on top of that, mental illness from your father, "good set".
But Alexis never said she hated you. Even though her Alexis Kaye identity has long been lost behind the mask of Punchline, she still has a heart and a brain, although not always.
No wonder Joker punished you. Wait, what happened this time? You were talking to Robin, seriously? Even Alexis rolled her eyes at that. The punishment was not very pleasant, two weeks without food. How nice considering that children are growing organisms.
But Alexis at this time could calmly eat watching your sad expression, maybe she is not as bad as others say and she inadvertently began to leave a few pieces of bread on table. And you really are quite strange kid and never liked bread crusts, so every time Alexis came back to get something from room she always noticed hidden bread crusts somewhere, under table, under closet, under curtain. She knows you're hiding it so Joker doesn't find evidence you've been eating, but her whole room is starting to look like a bread crust factory.
— "Hell."
Alexis mutters as she finds a new crust of bread, this time in her cupboard. Is this what people call creativity?