Complex sentence: Barclay's journal runs from 1832 to 1854, with most of the entries before his marriage in October 1844 and the birth of their five children: four boys and a girl.
Split into simpler sentences: Barclay's journal runs from 1832 to 1854, with most of the entries before his marriage in October 1844. Jane and Barclay had five children: four boys and a girl.