Thank you for your query on Healthcare Magic.
Is your child a preterm?
What was her birth weight?
Did she cry immediately after birth?
Any history of seizures in neonatal period?
Any history of jaundice
This information is important to comment on her present condition.
By this age she should have controlled her neck and she should try to sit with the support.
It looks there is a motor delay.
I advise you to consult your Pediatrician
for the assessment of development in all domains and for referral to an appropriate center for further management.
Hope I have answered your query.