In 1990, this NeXT Computer used by Sir Tim Berners-Lee at CERN became the first web server.
Mom: Do you want these? A friend gave them to me in the ’80s. You can keep them, or sell them.
(hands me a Ziplog bag containing two holiday-themed brooches which are most definitely not her style)
Me: Sure. They might sell. Thanks.
Mom: I know she bought them online.
Me: Online?
Mom: Yes.
Me: Then it wasn’t the ’80s.
Mom: Yes it was.
Me: The Web didn’t exist yet. She didn’t buy them online, or it wasn’t the ’80s.
Mom: I had a computer in 1989.
Me: That’s entirely possible. But you weren’t shopping online from it. Email didn’t even become massively popular until ’95.
Mom: Believe whatever you want.
“Believe whatever you want.” Now that there is a good rebuttal to remember for the future. I have no way to get around that one, because it’s apparently my PERSONAL BELIEF SYSTEM that is preventing me from, well, believing that this unnamed friend of my mother’s miraculously bought two costume-jewelry brooches online, years before any publicly-accessible online marketplace existed. (For anyone dying to know, AuctionWeb, which later became eBay, was founded in 1995 as part of a personal Web site.)
Grrrrr.
shoes and pie 
Ugh. My dad does this. *rantrantrant*
When I was in college in the mid to late ’80s, there was an embryonic intranet with a variety of bulletin boards. If your mother’s friend was at a university that had one of these systems, it is possible that she bought them from an ad on a bulletin board. Unlikely, but possible.
BTW, a boy broke up with me over e-mail in 1987. Pretty much my favorite break-up story to tell young whippersnappers who don’t remember life before e-mail. Because I am old.
I also used the earlier networks back in the day, but I know that when my mother says “online,” she’s not talking about BBS. :)
Maybe your Mom’s friend was Al Gore? Didn’t he invent the Internet? Maybe he had a computer in his basement and they’d get online and shop for brooches? Or something? :D