So far as I'm aware, there is no impediment to your neighbour again lodging an Application for Interim Orders with the CTTT, where as you've already found out an Adjudicator can make Orders without mediation.
One would hope that your neighbour's original Application (re the bathroom), her subsequent Full Application (mandatory), records of the Mediation Process, and the Determination would all be on file at the CTTT, and that all that would influence how they handled any further Application/s by this same person involving the same Strata Plan / Parties.
Once your proposed renovations receive the consent of the O/C and all Owners have the Minutes, I'd write to the CTTT outlining in general terms what is proposed with those further renovations, attach the relevant Minutes of the General Meeting, and appraise them of your concerns should they again favourably consider any Application for Orders by your neighbour.
Advice of a legal nature is best left to those Strata Lawyers who regularly post on this Forum, and based on my personal experiences, Simone of TEYS Lawyers has always been prepared to provide general comments via a personal approach on e-mail simone@teyslawyers.com.au ; mention your post on this Forum.