Thinking about it, ds has been able to write his name longer than 10 months, but I can't remember exactly when he started.
Anyway, as someone said, they all do things at different times. I used to worry because ds was always late in doing anything that required motor skills. He rolled at 7 months, crawled at 10 months, walked at 18 months ands talked at 2y 6m. He was toilet trained at 3y 2m.