Thank you Adam
I am confident that no SDLT return is needed, following the HMRC guidance, including the link below.
Stamp Duty Land Tax: transactions that don't need a return - GOV.UK
In addition to the fact that the transaction was a gift, there is no mortgage or other conditions which would trigger an SDLT liability. According to HMRC, no return is needed.
Can I send the application to the Land Registry without any kind of HMRC certificate or receipt?
Thanks