Newbury VR's show the following births :

Timothy, son of Christopher and Anna, born Oct 9, 1751 (1,438)

Josiah, son of Christopher, baptised Oct 19, 1755 (1, 437)

Josiah again, son of Christopher and Anna, baptised October 17, 1760 (1, 437)

Samuel, son of Christopher, baptised February 7, 1762 (1, 438)

Sarah, daughter of Christopher, baptised June 10, 1764 (1, 438)

These last four baptisms all took place in the 2nd church in Newbury, which later became the 1st church in West Newbury. This suggests that Christopher and Anna continued to live near his father in West Newbury and probably didn't move to New Hampshire until after his father sold the Newbury property in 1763 and bought in Methuen.