New flight attendants on all commercial airlines must undergo four to six weeks of training to prepare for these horribly rare in-flight crises. An additional 1-2 days of her training, primarily focused on safety, is repeated annually. It depends on the airline.
We recently visited Seattle, Alaska to learn about flight attendant training. This training includes training that simulates emergency landings, fire outbreaks, and onboard medical issues. This is what we saw.