Hi, thank you for your question. Please confirm:
-Are you in England or Wales?
-How old are the children?
My name is ***** ***** I have been a solicitor for more than 35 years.
\the answer is straightforward I am afraid.
If your ex is named on the birth certificate then you can only give your husband parental responsibility for your older child with the agreement of the father or an Order from the court.
The form you would need is here
Please ask if you need further details