When looking at the timeline of Sir John: Sir John Guildford, MP
it seems very unlikely that he had a daughter very close to sourced siblings that are born the same location (Hempstead) , but Catherine is born a different place (Dunstable) and only year to the sourced Elizabeth.
Is there any source that mentions Catherine Long as daughter of Sir John Guilford?
The attached source on Sir John includes the other sisters but does NOT list Catherine.
If such a source cannot be found, I do suggest a cut an freeze of the relationship to Sir John.
