I had another look for your grandmother in the 1911 Census, but no luck. I couldn't find Henry, Charles or Ernest either, which is unusual, and I am wondering if they emigrated. Or they became Census-shy, which some people did. Or I'm completely losing it...
What I did notice was a very strong Rulton presence in the registration district of Halstead, Essex. Probably related to your family because they seemed to be recycling first names with remarkable consistency - it's as if they decided on any child born in a particular year would be named the same throughout the wider family.
The most relevant facts for Maud's family:
Her parents married Mar Q 1892 in Orsett district. Sarah's name was Stripling. BTW he was 'Harry' in the index.
He was born (and registered as Henry) Sep Q 1869 Halstead.
1871 Census - we find his family in Hedingham, Essex. His parents were William, born 1836, Sarah born 1844. Siblings Horace J (1863), Charles (1866) and later Ellen (1874) and Fanny (1876).
William Rulton and Sarah Wicks married Jun 1859 Q Halstead.
Apologies for the typo above - Maud's mother Sarah died Dec 1906 and not 1901 - doh!