For reference to what you are facing go on Youtube and look up anything under “Karen behaviour’ because that’s what you are facing. A Karen’s defining characteristics are a sense of entitlement, a willingness and desire to complain, and a self-centered approach to interacting with others. Also “demands the world exist according to her standards with little regard for others. ” True that’s straight from Wikipedia, but it fits.
You almost had me convinced until “straight from Wikipedia” (a terrific resource but occasionally dangerously opinionated rather than factual).
I don’t think this is “Karen” behaviour, although it displays similar characteristics. This is one neighbour who complains about noise (to which she may be hypersensitive) to another who wants her to leave her alone.
And I don’t know if ignoring her is really an option unless Monique10 has developed Zen-like meditative powers to exclude all external stimuli.
But I agree that the simplest and most likely effective option is to deal with the problem at source. Perhaps it’s just saying to her, either to her face or in a note, “I’ve done everything possible to accommodate your wishes and address your complaints and I can’t do any more. In the interest of remaining on good terms, if you have any further problems, please don’t bring them to me, but report them to the strata committee who may be able to assist.”