Goodness!!
So many people onto the same family!! And we are all coming round to the same conclusions....
It is wise to be cautious... However, AYLMORE was not a common name in Whitstable area - In 1901 Census, your Hilda's family were the only ones. There is certainly not another possible Hilda AYLMORE, anywhere in the UK in fact - unless the name is again wildly mistranscribed, or the age is - and I doubt it, I searched just under "Hilda" as it was to find your one.
And - the Hilda Annie AYLMORE born in Steyning, Sussex 1891 - she died
in 1893 (FREEBMD) So she is not a contender.
Also FREEBMD is not a complete source - but even given that, if I search AYLMORE in Blean Registration District, there is :
1 Marriage - Porter to Ann KELSEY
0 Deaths
8 births - the first 4 of which are Hilda's younger siblings as per the 1901 Census - and I'm betting the rest of them are too.
You mention Hilda was supposed to have a sister named Polly and yet there is no mention of her in this family we have all found. "Polly" may simply have not been born by 1901 - 1908 and Polly may well be a nickname that bears no resemblance to her birth name. In 1901 Ann the mother, was only 31. She has 10-15 good child bearing years left. Indeed, I think it may prove that the other 4 Blean births after Ruby in 1901, may also prove to be siblings:
1902 - AYLMORE Ethel Colley L Blean 2a 922
1905 - AYLMORE Raymond Blean 2a 999
1906 - AYLMORE Ronald Pout Blean 2a 947
1908 - Aylmore Daphne Blean 2a 1031
The first thing is to establish whether or not the 1901 family is yours, and odds are that it is the correct one, and Hilda's birth was registered as KELSEY. I don't think there will be any better match. Luckily, you already have a family sourced DOB to check against it. If Hilda was illigitimate her birth certificate is probably not going to have any mention of her birth father - but it will confirm her mother's name....
Once that is done, that leaves the question open as to who Frederick was.
And - did he come before or
after Porter?
And - was or was he not Porter's brother?
And - what became of him
Hilda's 1918 marriage says her father was Frederick.
All romanticising about a lost beau who meets an untimely death on the seas and a brother stepping in as 'protector' to a young and bereft "widow" aside..... we must not assume Frederick was her birth father!! He may have been the man who brought her up . It is just as possible that Porter was her birth father and HE was the one who later disappeared or died and Frederick stepped in as the father figure to the family!
It would be interesting, therefore to see who Hilda's sister Maud names as
her father on her marriage records, if she married.
I cannot say if Porter's brother Frederick is the one mentioned on Hilda's marriage, maybe it was another relative, but not a brother - nor can I say if Frederick died btween 1881 and 1893 - I can find no FREEBMD death anyway.
Once establishing Hilda's mother was Ann Kelsey, I think could be an idea to get a birth cert of one the latest children you can get a record of - maybe Ruby, or take a bigger risk and get Daphne's and see who the father is named as - was it Porter?
Who were the witness' when Hilda married William Fuller MILNER?
Question: Where can one obtain Electoral Roll details for Whitestable 1918, to see who was at Hilda's marriage address.
Cheers
AMBLY
Later PS: Witness at Hilda's 1918 wedding were:
Ann POUT & E S HIGHSTEAD
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