Answer:
8 months : At this age a baby can sit independently without been supported.
Step-by-step explanation:
Usually a baby will begin to sit between the age of four(4) to seven(7) months. During these period, a baby can sit for a few seconds by himself but still the parents need to be around the child to hold the child when she losses balance.
A baby sitting down independently for a long period of time is not expected until the baby gets to eight(8) months of age. At this age she can sit for a long period but might eventually topple over,not due to lose of balance but due to loss of interest in prolonged sitting.