30 months girl,sometimes hv 4-5beat ankle clonus in both side when asleep.she hv a good milestone& not cerebral palsy.until when the clonus will occur?

The significance of: ankle clonus in infants/toddlers is not reliably known and relates to the number of beats (10+ seemingly important) and persistence at advancing age. The fact that your daughter has reached developmental milestones normally is very important. I would, however, have your daughter followed by a good neurologist as there are possible issues down the road. Good wishes:)