Kids are different though - I could share a bed with both dc1 & 2 when travelling, and indeed did - we all slept soundly. DC3 slept on my head though - nobody can sleep with an average sized18 month old on their head... If moved off my head he climbed back on or woke fully and wouldn't resettle, if physically held next to me he'd twist my ear or nose as a self soothing thing - but my ear or nose, not his own. I couldn't sleep through that even when (as back then was often the case) I'd only had about 4 hours sleep in 48 hours - the sleep deprivation was mood changing and rage inducing and I had to make him sleep alone eventually, though it took me til he was 2.5...
If it had been DH he'd been sharing with and I'd had another bed to get 8 hours in I'd have taken that if she was happy, but people are different, nobody's wrong for not having identical emotional responses...
Not all toddlers settle down next to their parents in a compatible with sleep way, they are all different.
My pesky head sleeper is a 1meter 20cm nearly 6 year old now and when over tired still goes into a state of extreme wiggling, squirming, kicking unrest in which tries to crawl under my skin and play with my nose and ear, and put his entire other arm up my sleeve til I can get him to bed, as if he thinks somehow crawling inside my cranium will be the only way he can rest... Whilst his siblings will nod off on sofas or rugs or chairs, or get a second wind and stay awake, if kept up too late... Kids are weird...
Just because yours snuggle down cutely for cuddly sleep and let you drift back off doesn't mean they all do...