If you already have a Will and you have more children, then we recommend that you review your Will with your solicitor to check whether it needs to be updated. If you are updating your Will this could be done by making either a new Will or a Codicil.
As mentioned above, we advise that any Codicil is professionally drafted as it may otherwise have unintended consequences. To be effective, a Codicil must be signed, witnessed and dated in the same way as a Will.