Demi: Shelby wants everyone to be regulars, so she would happily welcome Demi to The Doughnut Hole. She's also pretty good at recognizing when she's really bothering someone and making herself scarce, so I don't think they'd get off on the wrong foot.
Ria: I think they would too! And she's really impressed by Ria and all her work accomplishments. If Ria comes in regularly enough it's possible that Shelby's noticed her schedule and already has her coffee ready for her. Can't have the head of the ER late for work!
Nick: She doesn't flaunt the whole olympian thing, if that makes it better! It would really have to somehow come up in a conversation for her to say anything about it. But Nick and his optimism are always welcome in the coffee shop, and she'd probably feel bad about his knee and stuff, because injuries suck.
Kitty: And Shelby will love getting to know someone near her age! Though she can't relate to the mom thing (and probably thinks Kitty is superwoman for managing it), she would definitely love to see Kitty and her kiddos every once in awhile.
Sasha: Maybe he could come in with Max sometime? She will probably ask him about his tattoos, and there is always a possibility that they cross paths at the school, even if they won't have any classes together. She would be pretty flattered by the flirting (no matter how bad it was), since Sasha is adorable.
Bishop: Bishop will intimidate Shelby, so sorry in advance! Though if he's his usual charming self that will help a lot with their interaction. If he brought the twins with him she'd think they were super cute also.