The IGI has a marriage of Dorothy Quiggan and Robert Lewin on Aug 29 1861 in German.

1851 census castle Street Peel HO107/2523 p.46
Robert Quiggin head m 39 Clerk in timber yard IOM Michael
Dorothy Quiggin Wife m 32 IOM Douglas
Eleanor J dau u 11 IOM Peel
George u 7 son IOM Peel

1861 Census KK Michael Street Peel G9/4428 p 8.
Dorothy Quiggin Head wid 42 Grocer & Milliner IOM Douglas
George son u 17 Watchmaker IOM Peel
William R son u 6 IOM Peel

1871 census
Michael St. Peel RG10/5771 p 40
Dorothy Lewin Head m 51 shopkeeper/grocer IOM Douglas
William R Quiggin son u 15 draper? IOM Peel

1881 census Moss Side 54 George St
Mary A Quiggin wife m 23 IOM
Alice D dau 2 Stockport
Ernest W H son 6 months Stockport
Dorothy Quiggin mother w 61 IOM
Charlotte E? Cretney visitor u 18 IOM
Isabella Drake visitor m 37 IOM

1881 census Brisbane St Douglas
William Cretney head w 65 retired farmer IOM Marown
Lydia Esther dau u 15 IOM Marown
William Robert Quiggin son-in-law visitor m 35 Commercial traveller drapery IOM Peel

I did not find Dorothy in 1891.
There is a Dorothy Lewin who died aged 76 in the September quarter of 1895 in Omskirk Vol 8b page 604
Bruce