I have 2 dds, 6 and 4. They have been parented in a pretty similar way but they are different personalities. Dd1 is quite highly strung, drama queen, emotional; dd2 is laid back, easier, cuddly. However, the older one is a better sleeper and much more adventurous with food. The younger still gets in bed with us 3 nights a week and is a moderately fussy eater. Sil has a 3 yo who has always slept brilliantly and eats more than my 2 put together (not overweight BTW). Sil is more than a tad smug about this and puts it down to "recognising our mistakes with dd2" .
As a parent of 2, I see her as having been lucky with a compliant child - next one might not be quite the same. Good parenting isn't just about good eaters and sleepers is it???