Which of the milestones develop first

*Mirror play is attained by 6 months *Crawling by 8 months *Creeps by 10 months and creeps well by 12 months *Immature pincer grasp by 10 months *Mature pincer grasp by 12 months Ref : OP GHAI - ESSENTIAL PEDIATRICS - 8 TH edition page no 4 and 52