I only caught the last half hour of the movie so I don't know if I'm missing something. But Ouisa seemed pretty upset that she couldn't reach Paul while he was in prison. But what was stopping Paul from contacting her? He knew her name and all.
Assuming he was being sincere on the payphone about wanting to live with the family.
The story doesn't know.
What I mean is, the story ends before we learn Paul's fate, and that's kind of the whole point. Maybe he died, maybe he gave up on the whole charade. Maybe he's trying frantically to call her, but she's out wandering the streets whacking awnings.
We just don't know, and it's kind of important that we don't know.
She never knew his real name and he never told her so that she would have no real way to contact him. Even the gay guy who gave up all the info on those people didn't really know who he was.
I think she was foolish to waste her time trying to find "Paul" at the most he bilked her and her husband out of a night's stay and $25.00 when it could have been much, much worse.
In real life, "Paul" died of Aids.