Bring the document that links the two names, usually a marriage certificate or a legal change-of-name certificate, and present it alongside the parchment and the transcript. Ask that the offer letter use the name in her passport, and attach certified translations to anything not issued in English.
The chain between documents has to be visible without explanation
An adjudicator reads a file quickly and is entitled to treat an unexplained discrepancy as a discrepancy. A degree conferred under one surname, a provincial registration under another and a passport under a third is not evidence of anything wrong, but it is evidence of nothing at all until the connecting document is in the folder. Marguerite should order a fresh transcript, request a conferral letter from the registrar if the institution issues them, and keep the certificate that made the change lawful.
She should also read the employer's draft for small inconsistencies of the same kind: an abbreviated legal name for the hatchery, a worksite address that differs from the one on the lease, a supervisor named in one paragraph and a different manager in another. None of those defeats an application on its own, and all of them are cheaper to fix in advance than to explain at the border. Where an original is in another language, the translation must cover the whole document.