We moved here when DS2 was a toddler (18mths) and DD2 was born here. Both learned to manage the stairs in their own time - we did block them off for her when she was very little, just crawling, but at toddler age they both managed pretty well The biggest danger (and still is) is distraction - physically she is well able to walk up & down stairs, but if she gets distracted she can stumble.