"Somehow"? They would do so via a completely standard clause that enjoins any acquiring entity to honour the terms of the contract. I have never negotiated a contract that did not have a such a clause. Neither has anyone else who knows what they are doing.
Maybe she had incompetent representation. Maybe the arcana of this specific acquisition were such that any contractual obligations were effectively terminated.
But don't pretend for a moment that this isn't bog-standard, boiler-plate-level stuff. We know exactly how such contractual obligations would be conveyed across multiple acquisitions, mergers and organizational changes because we are used to writing contracts that specifically say "If you're acquired, the obligations under this contract are on the acquirer."