Testamentary guardian birth registered USA

My client wishes to appoint a guardian by Will for her son R currently 11 years old. R was born in Maine, USA to unmarried parents although both names are on his birth certificate. They separated a few years ago and my client returned to UK with R. R has retained contact with his father and visits him from time to time.
My client would be happy for R to go to his father should she die during his minority. However if his father was not willing / able to take on R or if R wished to stay in the UK, she wishes to appoint a close female friend as guardian.
My question to the forum is whether this appointment would be effective, given that R’s father has not acquired parental responsibility in one of the ways prescribed in the Children Act, or whether any parental rights he has under USA law are recognised under The Hague Convention or otherwise giving him the equivalent of parental responsibility in the UK? If the latter is the case, would the guardian named in the Will have to apply to court for formal appointment?
Grateful for any advice members can give.

Alexandra Taylor
Botvyle Consultants

Under English law an appointment of a guardian by Will to someone with out parental responsibility would not be effective if there is a surviving parent with parental responsibility. In this circumstance I would suggest that a detailed letter of wishes accompanies the Will explaining the full reasons for the appointment of the friend. The letter of wishes should take into account all of the issues in the Welfare Checklist within the Children Act 1989. In the event of the clients death and a dispute between the friend and the father as to who should care for R the letter could be relied upon within contested proceedings. Although the appointment would not override fathers position the mothers position and the reasons would be taken into account by the court as well as the child’s wishes and feelings and all the other matters within the welfare checklist. Ideally though upon the clients death if R is to stay with the friend and father agrees they could enter into a child arrangements order by consent to provide that R lives with the friend and spends time with the father, or that R’s care is shared between the friend and father. This would then afford the friend parental responsibility. The other option is to obtain fathers consent during the clients lifetime as to the arrangements and put in place arrangements prior to death. If the child is habitually resident in England at the time of death and remains there at the point of any dispute then English law should apply.
I hope that is helpful. I am a family lawyer and one of my colleagues (who is a STEP member) who I have worked closely with on similar issues suggested I may be able to help out with this scenario.
Kind regards
Jane Livingstone
Knights Professional Services Limited