going up to a toddler bed too soon?

How early do you think is too early to put a baby in a toddler bed? With my oldest he stayed in his crib till almost 2 1/2, I mean before then not long before then his crib was in the day bed layout but I think it wasn't until 2 that we did that. With our youngest who's 18 months he's still in the crib but will be going to the bottom bunk of a bunk bed with side rails sometime during this summer.

Anyways I have a friend who has an almost 10 month old and she's due in May so her boys will be 13 months apart. She plans on putting her youngest in a toddler bed that she's already bought and set up before her next baby comes so the next baby can have the crib. I know he's not my kid and she's going to do whatever anyways but what do you mamas think about putting a 10 month old in a toddler bed which is set up in another room? I'm also just gonna add in that he's not walking yet and can't climb things, which would just worry me more for him trying to get out of bed and falling or something.

My son was 13 months.. we had moved and instead of putting the full crib together, I just set it up for the toddler bed transition. He did great with it! I actually think putting him in at a younger age wad better for us because he didn't even try to get out of bed.