Technically, yes, the owners corp is responsible for the alterations – but that also means that theoretically you can remove them.
The new owner can say it has nothing to do with her – and you can say well, make it something to do with you or we will reinstate common property to its original condition.
In an ideal world, with your support, she could pursue the vendor for not fully disclosing the situation with the changes.
But what you really want is to get this all shifted to her responsibility so that the Owners Corp isn’t constantly being asked to pay for fixing work that should never have been done.