I don't think any of mine would have reason to recall her diving at the 2012 Olympics either, though the name might be vaguely familiar to Olivia (who probably didn't follow diving very much, nor would have been interested enough to watch the semifinals online if they weren't shown in primetime).
Ryan is my biggest optimist, but he'll also likely see her coffee/doughnut shop as competition so he'll be hesitant to get to know her. If Clem is up for it we could even do a line in which they have to compete over limited supplies at the sketchy grocery store or importing from the rest of the US as well. We'll have to see if they can develop some sort of friendship down the line, or if they'll remain adversaries.
Overall, all of my other characters would be pretty interested in patronizing the coffee/doughnut shop. Some more personality notes --
Pete is also a bit of an optimist, even if he hasn't had opportunity to show that much in game lately, and he gets along with people with that kind of personality as well. He would probably casually flirt with her, as is his way still, and he'd be all about real coffee and doughnuts in Austin. So it would probably depend on how she'd react to him, I think.
Nina would probably keep an eye on the progress of her shop and want it to succeed for the greater good of Austin. While she's also into the actual goods being sold, I don't think she'd go there herself very often since she tries to keep a low profile and is a tiny bit traumatized from the Hellhound incident. I think they would get along though if/when they meet.
Olivia will likely be polite at first, especially if they meet in the context of her shop, but if she ever hears about the Olympics thing, there will be a whole lot of jealousy she won't be able to manage very well. (I always had the headcanon that she never would have qualified for the 2016 Olympics, but she'd been training throughout what was there of 2016). We'll have to see what happens between them as the game develops, but I'm guessing it'll be negative from Olivia's side for at least a little while due to Liv's need to be in the spotlight and her general distaste for optimism as well.
Lastly, Cherry would probably get along with her, and I think Vic wouldn't have reason to be anything but friendly to her should they meet.