H.W.
A dear teacher friend of mine (who is now a mom of older teens) noticed this behavior pattern with her kids too, and suggested that for every day of the 'bad habit'/change from the norm (we all make concessions for kids when they're sick or traveling, right?) to expect three days of working to get things back to normal. This is not an exact formula, by the way, but all that to say, you may be in for a week or so of work in getting things back to how they usually are.
If it were me, I'd expect that she's going to get up and that she's going to use the reasons that were previously valid to get the same parental attention. ("I'm sick/I'm scared" as you wrote.) At that point, not a lot of talking, just take her hand and walk back to bed. I wouldn't engage in trying to do a lot of explanation of why she's not sick or anything like that, just "You're in your own bed tonight. Go back to sleep. We'll come check on you later." Keep taking her back to bed. As I said, not a lot of explanation nor do you try to reason with her. Try to keep your emotions neutral and keep engagement to a minimum.
Sometimes, with my son, I'll appoint one of his bedtime buddies (animals) to 'watch out for' him. My short explanation to him, when he gets up is "You're fine. I'll see you in the morning." and then no more conversation. No hugs or kisses (don't want to validate their waking with positive attention) no "I love yous". Just "You're fine. I'll see you in the morning."
Be patient, be consistent and know that she *will* get back in the routine if you don't give it any more attention than is due. This might be hard if she's getting emotional, but if you expect her to sleep alone and she had no problem with it before, it will be best to minimize the issue.
Good luck! And I wish you and your husband plenty of patience. I know how much I dislike being wakened. We also have a rule in our house that if our son wakes us for no *real* reason (wet accident/throwing up, etc.-- he hasn't had any nightmares as of yet), there's no video/tv time for that day. I hate to punish it, but our sleep was getting wrecked by a little boy who wanted "company" at night. ugh! You have my empathy. :)