It is down to the home owner to file tm30 and in the OP case if he does it on her behalf law they will want a form signed by her. I had to do this, pain in the arse it was.
I guess it depends if the OP is just a tourist not likely to return for long time or soomeone whi lives here on visa exempts which does not seem the case or they would probably have not asked the question :-)
Thats why I mentioned if they had to visit immigration outside BK. Reently on here it appears TM30 getting more of an issue in many places outside BK. Yes if in hotel then hotel would have filed it but they did not say if they were in hotel for over 30 days. Many people use airbnb like I do, some landlords on airbnb file them some dont. Just saying that these days people looking to do more than 30 days probably better off getting a visa in the first place to avoid having to go to immigration to extend exemptions.
surely if they want extension and go to immigration and they have not had a TM30 filed, they are likely to get fined for that on top of the 1900 for extension? I went to Prachin and they asked for mine, had to drive back to get inlaw's written permission to do TM30 on their behalf, also had to go to police station for a replacement tm6 exit card (at least that was free a I did not have 2 baht on me only 1000 lol) all of this for 2 days extension i needed, same as OP.
If you don't have a TM30 done and need to go to immigration outside BK I would pay the fine. It took me 2 days and 3 trips to get mine done and had to do tm30 same time lucky I was not fined for that.