Answer:
She wants to work in a flower shop.
Explanation:
This is the main reason why Liza seeks Higgins's help. Liza is interested in working in a flower shop, and because of this, she wants to receive speech lessons. However, Higgins cares little about her goal and instead decides to use her as the subject of a social experiment. He wants to retrain Liza so extensively that she will pass for a Duchess.