While the tenancy continues, the terms of the original tenancy remain the same. Therefore you cannot set a new rent (or increase above the guideline) unless the tenancy ends and the original tenant moves out.

For the tenancy to end, the tenant would have to physically leave, or you would have to attempt to enforce the notice she gave to you by filing an L3 application to terminate the tenancy with the Landlord and Tenant Board.

You would likely get a termination order if her original notice contains the required elements. Please see our fact sheet on ending a tenancy here: https://landlordselfhelp.com/media/Ending-a-Tenancy.pdf

The tenant could, however, still file to set the order aside, get a hearing and plead her situation before the Board Member, but it is hard to predict the outcome of such hearings. In the meantime, it would not be practical to re-rent the unit, as it creates great confusion for the next tenant as to when or if they can legally move in.