Kids with an adventurous spirit have a way of getting to where they want to be.
Unconventional forms of assistance are by no means unacceptable. You don't need a step-ladder for climbing - heck, if trampling over toys, crawling along the back of the lounge, clambering up on the coffee table, gets you where you want to be then why not?
What do you clamber over, jump from, scramble through to get to where you need to be?
The best stepping stones aren't always purposely designed that way.