Thanks Sue .. I think we are coming to the conclusion that we will have to search 1877 & 1878 .. perhaps she had a child before Walter. Perhaps have a search done 1876-1880. I sat with a piece of paper and worked out when she "could have" had baby.
Your question about Census .. on 1881 Walter is aged 1, Eleanor Maud is 8 living 92 Strand Street, Onchan. On 1891 Census William H is aged 9 with siblings Walter, Eleanor, Amy, Eleanor (interestingly she is aged 6 on this Census, she was age 8 10 years previously) which is strange.
If we don't find his birth will have to assume he was either born at sea or he wasn't Annie & William's child.

Thanks...... Barbara