The length of a session varies a lot depending on the baby.
My sessions are super relaxed & fully baby-led and therefore, we will go with the flow of the baby in a relaxed and calm way. As all babies are different, a session typically lasts anything from 1.5 - 3 hours. This provides plenty of time for feeding, soothing & settling.
Parents often panic if their baby starts crying or wont immediately go to sleep during a session but that is completely normal. Sometimes (albeit rarely) a baby starts the session asleep and stays asleep the whole way through but usually a baby needs a bit of gentle encouragement.