The question was: "Are we waiting for Laura? No, we're not waiting for her any longer.
I put: Nous attendons Laura? Non, nous ne l'attendons plus.
This was marked incorrect. Please explain why the pronoun "la" can't be used here, in abbreviated form with an apostrophe.
The lesson that accompanies the question does not deal with pronouns.
I can't see why my answer is wrong.
Please advise.