One toilet is actually one more than most campaign settings have.
Commentary by memnarch (who has not seen the movie)
Next stop, Tatooine? ... Yeah, that tracks. It's gonna be extremely unlikely to be back on the salt desert planet; we didn't see anyone except the Resistance and those salt foxes. And introducing yet another desert planet when Tatooine is orbiting right there would just have people complaining it wasn't Tatooine anyway.
The more interesting question at the moment I think has to be "how old is that little girl now"? 30-40 is the obvious answer of course, but there's nothing stopping her from being that old at this moment. With time shenanigans, the young girl could have had the laser sword between Rey and Palpatine/Palpaclone or even be completely unrelated to the laser sword. Heck, that scene with the lady holding the girl looked like Rey, so it's totally possible! .... In the comic anyway.
Transcript
Rey: So Palpatine had Luke’s sword. How did he get it?
Darth Kanata: No idea. Galaxy’s full of weird connections and paths. You know?
Rey: The sword visions...
Rey: The Jedi texts say they show past echoes. Maybe from between Luke losing it and Palpatine finding it.
Rey: The girl!
C-3PO: Who?
Rey: This young girl in my visions. She keeps saying “Bring it to me”. She’s got to be the key to this whole thing!
Finn: So who is she?
Rey: I don’t know. She’s small, dark-haired, scared. Being abandoned in some desert.
Poe: Tatooine!
Chewbacca: Oh come on. The odds of any given desert scene being on Tatooine are... literally astronomical.
Poe: We’ve only seen one desert planet in this whole campaign. Statistically, it’s gotta be Tatooine.
Chewbacca: By that logic, the Galaxy contains precisely one comet, one asteroid field, one Sarlacc, and one toilet.
Poe: Hold that thought...
Chewbacca: I’ve been holding it for a long time.