In answer to your question – this is from information recorded in a family tree that is at Rydal Mount in the Lake District.
The Poet Wordsworth had 5 children – John (1802-1875) Dorothy – Dora (1804-1847) Thomas (1806-1812) Catherine (1808-1812) and William (1810-1883)
William (b 12th May 1810 d 7th? Feb 1883) was married to Fanny Eliza Graham (youngest daughter of Reginald Graham of Brighton)(b 2nd Jan 1821 d 28th Aug 1888)
Their Children were:- Mary Louisa, William (1851-1851) Reginald Graham (1852 – 1919) Gordon Graham (1860-1935)
Mary Louisa (1849 – 4th Aug 1926) married William Crosbie Siddons Mair (Colonel)(b1839 d 28th July 1918 at White Moss Rydal) (Son of Major Arthur Mair) – there is also extra information linking him to the actress Sarah Siddons.
They do not seem to have any recorded offspring
Hope this is of some help – but there is a little more info at Rydal Mount.
Thank you so much for taking the time to answer this for me, Dorothea Clare Pine. Now I have the full name I can hopefully trace where Colonel Mair came from originally and see if there is any link to my great grandfather. Never done this before brut seeing our family name in such unusual circumstances has got me very interested in the background story. Thanks for your help. Carole Mair