No, putting a 3-month-old in the 3D Lite or 3D Mini Stroller is not recommended. The strollers are designed for babies from 6 months old due to the seat's design and support level. Infants younger than six months old may not have the proper neck and head control to sit comfortably in the Stroller. It is best to follow the manufacturer's guidelines and seek advice from a healthcare professional regarding when it is safe to use a stroller for the baby.