A couple of things here. This owner has altered common property and the strata manager doesn’t have the authority to allow that or otherwise. So that’s one route for a solution.
Also, residents are not allowed to do anything that causes a nuisance to other owners – and by nuisance, Section 153 means things that affect their health or wellbeing.
With those two pieces of information in your back pocket, you can talk to the perfumed princess and tell her she needs to change her habits.
Then, if she ignores you, you can call the strata manager and ask him when he held the general meeting that passed the by-law that allowed your neighbour to install a fan on common property that poured toxic fumes into your flat.
If the ventillation is inadequate, it should be fixed in such a way that takes smells out of your bathrroom, not pumps them in.