Francis was regarded by his father, William Crawshay II, as idle and frivolous and as such was usurped as heir by his younger half brother, Robert Thompson.

In 1837 he married his first cousin, Laura, a daughter of Richard Crawshay II ( a companion portrait of her is also in the Collection) and they had nine children. His wife's mother, Mary Homfray, was related to his mother, Elizabeth Homfray. These Norfolk based Homfrays were part of the same family that owned the Penydarren Ironworks.

Francis was very popular with the workmen because he was the only one of the family who could speak fluent Welsh and he was a great humourist and fond of practical jokes, unlike his rather serious and severe father and half brother.