These verbs take a direct object, so the right pronoun to use is "la". However, saying "le" is correct in some regions (mostly in Spain) where it's used as a courtesy pronoun.
As a side note: "Está siendo ayudad
a" sounds really strange. It's not incorrect, but the passive voice is not commonly used in Spanish to address someone directly. It's better to use the same structure of your previous examples. I'd say something like "¿Ya la atienden / ya la están ayudando, señorita?"
