In 1946 the house and its 960 acres passed to James' daughter, Helen Maud Stanham,  who was married to Major General Reginald Stanham and was living in England at the time. Helen had grown up living at "Gilbulla" at Menangle and she was married from there in 1919 to R.G. Stanham, the British-born former private secretary to the NSW Governor. The couple later spent time on military postings in Essex and Sri Lanka.

 

Reginald became the British Army Paymaster General during World War Two and was knighted in 1948. When Helen unexpectedly inherited Camden Park, they decided to take up the opportunity and to move to Camden Park, mainly for the sake of their only child Quentin. Arriving in 1947 they quickly became very active in the Camden community. Helen was invited to be a patron of a number of local organisations and took a great interest and enjoyment in improving the beautiful gardens at Camden Park. Gardeners recalled how she would take a daily walk with the head gardener to agree on the work for the day and to encourage them in their projects. In the 1950's they held some open days for the public to visit the gardens as a fundraiser for charities. Lady Stanham and her English housekeeper also developed the lower gardens for the production of cut flowers for the Sydney market. It was Lady Stanham who requested her son Quentin to change his surname to Macarthur-Stanham in order to ensure the continued association of the name Macarthur with the property.