Take things easy and let your child develop at her own comfortable pace.
Milestones are not carved in stone.
Quit freaking out if your eleven month old is still completely toothless. Cutting a tooth does not mean they have developed a new bone, the teeth are right there under the gum, it WILL come out. Sit tight and in the meantime enjoy that absolutely adorable gummy bear.
(PS: its normal for a baby to not cut her first tooth till eighteen months).
Some children will walk, talk and sit up later. It does not reflect on the intelligence and acumen they will have as adults.
In the end, don’t let your worries become obstacles to enjoying your new baby to the fullest. Be assured that the long days and sleepless nights will amount to something spectacular.