**** In addition to «removing» stress at bedtime ****, it can also help the infant to re-settle themselves if they wake up during the night — which means lots more sleep for everyone in the house! (ecochildsplay.com)
At 19 months, toddlers still need a lot more sleep than adults, and they will probably spend more time sleeping at night and less time napping throughout the day. (howtoadult.com)