When I told my mom, I was already considering getting a house with Rachel (non-romantic/sexual partner), her other partners, and then seeing if Jon and Lora would be interested. My mom knows that I would much rather have roommates (or co-buyers) and live in a bigger place, than be solo, but crammed in a small place. Even though I was poly for quite a while with Rachel as a primary partner, I never told my mom, in part because I knew she wouldn't get it. As in, she really wouldn't understand the concept of wanting to spend the rest of your life with someone who you weren't married to and/or romantically/sexually involved with.
But when I started seeing Jon seriously, and was still involved with several other partners sexually (who I had much more casual relationships with), I knew I had to tell her, because I could easily say something like "Oh yeah, Jon and I are still dating. Yep, I saw Bob the other night." And she would ask something like "Why are you seeing Bob if you and Jon are dating seriously?" Well, mom, because I'm still having a relationship with Bob. And Jon knows. And he's fine with it. And no, we're all not just crazy, slutty, free-love hippies (which I see nothing wrong with, but isn't who we are, so...trying to get things straight for the mom).
But yeah, if Lora's family lived further away and there was less of a chance of them stopping by, I wouldn't be as concerned about her family knowing. They don't like, like 20 minutes away, it's more like 2 hours. But they do come to our town semi-regularly to go to a particular shopping complex, so it's not beyond the pale for them to possibly be in the neighborhood and decide to stop by.
The other thing I'm concerned about (but I've only voiced to Jon) is...I don't know if Lora's family might be more/less/as upset that she lied and/or misrepresented her living situation for at least a year. I think that most parents (or even people, really) would be upset to be lied to (even if it was a lie of omission or Lora making random excuses for why the family couldn't come to the new place) for a long period of time. If that's the case, I hope that Lora explains to them that that was HER idea, and that the only thing Jon and I had to do with it was that we were aware she was doing it.
Jon seems to feel like her family won't feel like it's a big deal, and that even if it is, it's Lora's thing to decide. While I agree that it's Lora's thing to decide, I really just hope that Lora is honest about the fact that SHE was the one that didn't want to tell them, and most especially, that it wasn't *me* trying to be sneaky or something. I have a lot of concerns about that. At some point, I should probably post about why I'm feeling concerned about Lora's truthfulness.