19 Month Old Daughter Suddenly Refuses to Sleep, ESP in Crib

She was just getting over her illness and you went tough love on her. Broke her trust. No wonder she does not want to sleep in her bed. Now you'll have to figure out how to make amends.
You'll have to really become patient. That is one of things we learn in the on the job world of parenting. While returning to normal do not use CIO or other child busting techniques. The thing they really bust is your good trusting relationship with your child.
If you had a bedtime routine before go back to it. A couple of add ons like a story and a song might be very helpful in getting her into a relaxed before bedtime mode.
As we are coming up to a time of more daylight when you tell her it's time for bed open the window and let her hear the birds singing their night night song.
It worked with my pre-schooler to get them to go to bed at their usual time.

Hi L.,

Maybe it's time for a big girl bed. Try a twin mattress on the floor (put the crib away). Stores like Big Lots and Sleep Train have some good deals on name brands.

Blessings.....

Wow, you've been really lucky up until now with the sleep thing! I think most every child has a sleep issue at some point in their childhood, though. I think some kids get scared when they are sick and don't want to be alone. She might go back to the usual routine when she's all better, or might not. I wouldn't rush to a bed though at 19 mo. It's safer for her in her crib.

You could try starting a new bedtime routine. You may not have needed one before if she was asking to go to bed. Maybe a bath to relax her, then look at a book together, then put her to bed. If she cries when you leave, you can try this:

Let her cry for a minute or 2 and see if she settles herself. If she doesn't, go in and reassure her that she's ok, that it's time to go to sleep. I used to tell my children that mommy and daddy were going to sleep too. Then I'd list all the people they knew and say they were going to sleep. Then I'd even add animals, "the bunnies are sleeping and the birdies are sleeping", etc. Sometimes this works. Anyway when she calms down leave the room again. If she starts crying, wait maybe 3 or 4 minutes this time, and go in again until she settles down. You may have to do this several times before she falls asleep. Each time add a minute or so to the time that you wait to go in. This is the Ferber Method, by the way.

Hang in there Mom, it'll pass :)

Neither of my kids lasted that long in a crib. Parly because I'm short, and I had the most success when I put them to bed asleep. Anyway, we put a twin mattress on the floor. This allowed us to comfort them in their own "bed." It also gave them that feeling of not being caged in. The both sleep great, and we got more sleep that way. We also let them join us in the middle of the night if they are scarred or not feeling well. It works for us.