So, I've continued playing, and still don't have the greet warmly option, but noticed that as long as my Sim is not uncomfortable, she can greet patients normally.
I'm doing the Cats Rule, Dogs Drool challenge, and am just starting out, so all my equipment is beat up, and makes my Sim uncomfortable, so I have to walk outside, and then greet my patients.
Not ideal, but until I can afford to upgrade my clinic, at least it's a workaround for now.