It drives me crazy that Lane thought she owned the house

I watched September again recently. I don't dislike it; I think Elaine Stritch makes the movie. The other characters are all such milquetoasts, whining and mooning over someone who doesn't return their feelings, so Strich's character brings some much needed interest and life to the story.

But every time I've seen it, it has driven me nuts that Lane is trying to sell a house she doesn't own, that she doesn't know she doesn't own it. You have to pay property taxes and insurances on a home. Just because her mother might've one time, while drunk, said this is your house, Lane believed she actually owned it? Had she ever seen any paperwork anywhere ever that had her name on a deed?

That's just a practical reality, and ignoring it for sake of story takes me out of the movie.