There is just no written text about the son George Rooke (1702-1739, that i can find.
His mother died at birth in 1702 and his father, Admiral George Rooke was away often.
However, the father remarried again to a Catherine Knatchbull in 1706, so i suppose that the young George lived with her, he then being only 4 years old, but there is nothing to confirm this.
Upper-class people tended to have more than 1 residence at a time. There might have been a house in "Town" and a house in the "Country". Depending on the man's position in society, his wife may have spent long periods in "Town", running the town-house, entertaining her husband's guests and socialising. Children may have spent the greater part (or all) of their time at the country home, which was generally a healthier place for children, perhaps looked after by staff (nursemaid, governess, tutor).*
It's possible that Catherine didn't have much to do with her stepson. It may have depended on the admiral's purpose for marrying Catherine - was it for money or social or political connections, or to breed more children or to act as a social hostess or to be a stepmother, or even for love.
Jane, the admiral's mother, was alive until 1711. She may have been overseeing her grandson's care while his father was away.
Added. *As suggested by Top-of-the-hill reply 59.