Jeff – as it would be unusual for “rot” in the concrete sub-floor to be limited to the trafficable areas of the kitchen, it sounds to me like the Owners Corporation (O/C) took a minimalist approach to the original rectification works.
The best approach in my opinion would be for you to obtain a quotation for the remediation of the previously un-repaired areas of the kitchen floor, and for your partner to include that with correspondence to the Secretary of her Executive Committee (E/C) seeking advice regarding any requirements that it may have with regard to her proposed renovations (the scope of which should be outlined), setting out the circumstances that you’ve described here, and requesting that they either arrange for the previously un-treated areas of the kitchen floor to be repaired in a timely fashion or to reimburse her costs of having that done as part of the overall renovation.