Thanks for doing that Joe -
In regards to Philippa's birth date, apparently a marriage between Edward and one of the Hainault daughters was proposed back in 1318 or 1319 (perhaps this is early 1318/19) and Walter Stapleton, Bishop of Exeter, was sent to inspect the proposed bride. His very thorough report includes the information that 'she would be nine years old on St John's day to come' (24 June is St John's day) but unfortunately the report doesn't actually name which daughter is being inspected.
It was always thought that this was an inspection of Philippa, because they eventually married, but Cawley, thinks it is the eldest daughter Marguerite, and Lisa Hilton in Queen's Consort: England's medieval queens, suggests it could have been Sybella, another daughter who died sometime between 1319 and 1326.
Cawley cites a recent study of the Hainault daughters by Bert M. Kamp for a birth date of about 1314 for Philippa, but then has her birth as possibly between 25 January and early February. I'm not sure if Kamp is still the source for these dates or he is using some other source?
In regards to Jane Southerey's LNAB, I think the profile manager is not very active at the moment, so I'll leave it for a few days and then go and make the change myself. I would like to make the EuroAristo project the main profile manager for most of these profiles, in line with accepted policy.