In the 1901 census James Beeching was Head of the household in Brenzett, Kent, a village on the Romney Marsh. The page lists Wife, Eliza Beeching, then three Sons, a Daughter and another Son who was not yet 1 year old. The next line on the page is Annie Maria Stickells, Relationship Sister, Occupation Visitor, age 28, followed by Elizabeth Harriett Stickells, Daughter age 2.
Based on the position in the list, and the surname, I think that Elizabeth was the child of Annie on the previous line, and not Daughter to the Head of the household but actually his niece. We know about the difficulties of connecting a niece to her uncle and aunt (see The Long Niece). However, in this case we seem to have the child's mother present in the household, Sister to the Head, so surely it is a straightforward situation!
The census says Annie Maria Stickells was the Sister of James Beeching. As the mother of a 2 year old, and with a different surname to her brother, we would expect to find a marriage between Annie Maria Beeching (or just Annie, or even Anne or Ann, perhaps) and a bridegroom with the surname Stickells (or some variant spelling, perhaps). However, I have not found any such marriage registration.
Turing to the GRO Online Index, we can look for the birth registration of young Elizabeth Harriett Stickells and check her mother's maiden name there. Indeed, there is a single candidate record and the good news is that it has the expected name, year and county. However, the other news is that the mother's maiden name was recorded as Shorter, which is nothing like Beeching.
How did James Beeching come to describe Annie Maria Stickells, née Shorter, as his Sister on the census? Was she actually his half-sister with a different father and surname? In the previous census, in 1891, James was with his Wife, Eliza, and three Sons. Ten years earlier, James, age 18, was with 2 older Brothers, William Beeching and Richard Beeching, then the census before that James is one of 5 children between the ages of 2 and 12 in the household of John and Sarah, all with the surname Beeching. All rather straightforward and not providing any clues about the Shorter connection.
Then revelation! Between the census with the Brothers and census with the Wife and children there was a marriage - James Beeching married Eliza Shorter in 1883. So, Annie Stickells, née Shorter, is the sister of his wife rather than himself. What a lot of confusion because the ink said "Sister" but missed out "in-law".