The Queen of Hearts' animosity towards Alice stems from a combination of factors, primarily a disruptive incident and a subsequent accusation.
After Alice, along with the Cheshire Cat and Tank, allegedly caused a ruckus at the Queen's croquet party, the Queen developed a dislike for her. The specifics of this "ruckus" are not always explicitly detailed but generally involve Alice's unintentional flouting of Wonderland's peculiar rules and customs, leading to chaos and embarrassing the Queen.
Adding fuel to the fire, the Queen readily believed the Knave of Hearts' accusation that Alice stole her execution wig. This solidified the Queen's negative perception of Alice, giving her a concrete reason to pursue Alice's (attempted) execution.
In summary, the Queen of Hearts hates Alice because of a disruptive incident at her croquet party, followed by the Queen believing Alice stole her execution wig. This combination cemented a strong dislike in the Queen's mind, leading to the desire for Alice's execution.
