Hi CheyenneDonna
Found this link
https://www.mobileread.com/forums/showthread.php?t=82030
It seems that Sony to Nook is ok. I have tried the other way and it definitely doesn't work. I believe B&N are using your account name and credit card to unlock content.
So even using the same email etc. for all accounts it won't work. One of the reasons I liked the Sony was because it was more open than say a Kindle or Nook when it comes to paid for content.
Interestingly I downloaded one of the free B&N books to celebrate the 4th of July and they are DRM'd as well even though they are all PD stuff.