there probably is a standard lease but unless both parties have signed it, it would have no standing.
Your best avenue (and i have to admit my knowledge of WA strata law is sketchy) is to pursue the owners rather than the occupants. The parents are the proprietors – send them the Notices To Comply with the by-laws rather than the leas, and follow up with orders. By the way, over here in the East we call this Brat Dumping (or, at least, I do)
Schedule 1 standard by-laws for WA say this in Section 1 (my emphasis):
(2) A proprietor, occupier or other resident of a lot shall —
(b) not use the lot or permit it to be used in such manner or for such purpose as causes a nuisance to any occupier of another lot (whether a proprietor or not) or the family of such an occupier;