Veronique also acts as the Juve midfielder's agent and Tuttosport says her intervention last Friday saw the move fall through.
Last week, Rabiot was contacted by phone directly by United manager Erik ten Hag for an informal and serene chat, in which the player - according to friends - appreciated what the coach said.
In the meantime, United had reached an agreement with Juventus to sign Rabiot for €20m plus bonuses. While a four-year contract worth €6m-a-year plus bonuses had also been settled, with only the forms needing to be signed.
United footbal chief John Murtough was in Turin on Friday to meet Rabiot face-to-face and confirm the move.
But then Veronique intervened with demands of her own, including a Champions League qualifying bonus and the same salary as Bruno Fernandes, around €10m-a-year. Mrs Rabiot also demanded a commission for her services.
Murtough returned to Manchester without an agreement, but remained open to negotiations. However, with Veronique not returning calls over the weekend, United had given up by Monday.