I’ve started co-sleeping with my toddler and don’t know how to stop

Co-sleeping, it's often one of those things you think you'll never do PK (pre-kids), but then end up doing at some stage. Sarah has started sleeping in the same bed as her toddler, because it's just easier to get him to sleep - and stay asleep! So does it really matter, or should she find a way to stop?  See omnystudio.com/listener for privacy information.