The online Official Roll of the Baronetage shows the Sullivan of Thames Ditton baronetcy as being vacant. Having checked DPB online I see that the 9th Baronet, who according to DPB2019 was resident in Florence, Oregon USA, and who did not use his title, died in 2022.
His only son (Sir) Charles Merson SULLIVAN b 1962, resident according to DPB2019 in South Molton, Devon and a veterinary surgeon, has succeeded as 10th Baronet subject to proving his claim and being entered on the Official Roll. He m 1993 Helen Mary ALEXANDER. They have issue:-
Alun David b 1998 ha
Hannah Robyn b 1996