Thanks, Erica, for giving a push along on my queries.
I found a couple of conflicting records for Anthony, who was not the original focus of my inquiry, but in looking at the data on him and his siblings, and Sir Hugh's wives, it seemed that there was something missing somewhere.
I have found a couple of records which suggest that there is conflict about Anthony's mother - one says that his mother is not known, while another suggests that he was the son of Sir Hugh's wife after Anne, i.e. Blanche Castell. One of the two sources also suggests that Anne may not had been Sir Hugh's 1st wife, but I could see no information to substantiate that.
I think that some of the information on the About tab for Sir Hugh might have been taken from one of these two sources (but without the source being referenced), or maybe Wikipedia....not sure.
It is not inconceivable that Anne might have been the adoptive mother of Anthony, if he was Sir Hugh's son by another woman while Anne was still alive, but then, the question of Anthony's legitimation, or otherwise, as Sir Hugh's inheritor, being - apparently - his first born child, might need further investigation. There is a hint as to his status within the family in the wording of Sir Hugh's Will. See link below.
The links for these sources are:
1. https://www.wikitree.com/wiki/Space:Sir_Hugh_Vaughan (This refers to Sir Hugh's Will and provides a transcribed copy of it...)
2. https://www.wikitree.com/wiki/Vaughan-1128
3.https://archive.org/details/middlesexpedigre651914/page/64/mode/2up... (I think this was already posted by Anne)
4.https://gw.geneanet.org/donmac?lang=en&n=vaughan&oc=0&p...
From Sir Hugh's Will (Erica, thank you for pointing me in the right direction! I now see the significance of your advice :)) , it could reasonably be concluded that he had 4 daughters with his wife Blanche Castell (Katerin, Elizabeth, Anne and Jane) and three sons - Anthony, George and Frances...all of whom appeared to be under the age of 21 at the time of Sir Hugh's death.
It isn't clear (from my reading of the will) whether all the sons were from Sir Hugh's relationship with Blanche.
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I hope this information may be helpful.
Also, would it be useful to cross-reference this Discussion under the profiles for other members of Sir Hugh's family.....?