Can children with autism have a bigger shaped head?

No. Unless there is an underlying case of macrocephaly from hydrocephalus the "standard" autistic child has a smiler size head to anyone else.
Several studies of ~. Small numbers of children with ASD show a 29--37% incidence of macrocephaly (head circumference > 97th%ile), instead of the expected 3%. Head circumference is usually 25th-50th%ile at birth, with accelerated growth between 6-12 mos. In some studies & by 3 yrs. In others. Some think this is related to the lack of normal "pruning" of neurons & their connections that is seen in neurotypical children.