Research does show that exceptionally bright people often do things for the first time earlier than average. (Like teach themselves to read when they're one, or whatever.)
But that's not always the case. For instance, Albert Einstein (the ultra famous scientist) didn't speak till he was nearly two.
And there are famous athletes who learned to walk at 8 months and others who learned to walk at 18 months.
So don't worry about it. Everyone has a different 'timetable' for their development.