You keep repeating yourself but you still aren't making any sense.
I'm not going to continue with this line as you just won't listen to facts and reason.
I don't know what you keep rambling on about.
The birth cert for Ada (who is definately Walters sister) lists her parents and states Walter as her eldest sibling and Charles as the 2nd eldest sibling.
Stating AGAIN that Walter was the eldest is just rambling as we have already established that...more than once, provided a cert to prove that and discussed that before.
Repeating and repeating isn't convincing anyone or helping your family tree search.
The facts have been sat in front of you.
It is up to you to cointinue with the search and confirm/deny what has been found.
The births of children to MAA LOUEY and Sarah WATSON/TALLENT (variants) have been posted MORE than once.
The marriage for MAA LOUEY and Sarah TALANT 1877 has been listed and it "matches" with the date of marriage given on the childrens births. (more than one childs birth has this 1877 date as the date of parents marriage)
There's no point in myself or anyone else researching this line any longer as you won't accept the facts placed in front of you.
Stating what you say "everyone in the family knows/says" isn't factual evidence of anything except family story/gossip.
Ada's birth cert (which lists Walter as the eldest born 1879 and Charles as 2nd eldest born 1881) sealed it for me.
Good Luck with your research