When they can sit up on their own.
between 6-8 mmonths
Some babies sit up by 6 months. Apparently, however, not sitting up by 9 months isn't a big deal either. See the Related Link to a video regarding a baby's milestones - sitting included.
There's a range, but most are able to sit up (if you put them there) at 4 to 6 months.
Babies develop at their own rate, but yes, a 4 month old may be able to sit with support. My 4.5 month old has learned to sit for short periods of time without support. I don't find this answer to be credible. Most babies do not sit on their own until 6-7 months of age. My son held his own neck up at only 2 days old and sat up on a boppy at 3 months old for 10 to 20 seconds at a time, but they fall left or right. At six months they learn to hold their toes or an object between their legs which keeps them balanced. Every baby does things at their own rate but a four month sitting up all by themselves is quite unbelievable.
There are many 3 month old babies that can sit with support. You do need to make sure the baby can hold their head up.
Most babies sit by self in 6-8 th month. However it all depends on his moments from Day-1. As parents/guardians make the baby sit against couch with support, Regularly massage babies to give strength and comfort them with pats and hugs. Push toys away from them so that they stretch to grab, etc..
Infants can sit with support at about three to six months of age. Some babies will be able to do this easier than others and will have stronger necks and backs.
Yes the mother will "sit on" the babies for the first while and when the babies get too big then she will still cuddle with them till they fly away.
No they cannot until they are at least 45 lbs or 9 years old.
they sit on them
About 15 or 16.