I can add a little bit of information which may help:
In his will dated 17 Jan 1749 Richard LOVETT, taylor of Chalfont St Giles, named the following individuals:
Son Richard LOVETT (executor)
Dau Ann WEBB
Dau Mary, the wife of Thomas PARKER
Dau Elizabeth WOOTEN
Gson Thomas PEIRCY
Gdau Hester PIERCY
Gdau Sarah LOVETT
Gdau Mary CLARK
Gson William CLARK
Gdau Mary PARKER
Gdau Elizabeth PARKER
Gdau Hannah PARKER
Gdau Ann PARKER
Brother Timothy LOVETT
Although brother Timothy is mentioned in the above will it would appear that he had pre-deceased his brother. His (Timothy LOVETT, barber surgeon of Amersham) will was dated 1 March 1727 and proved 2 May 1729. In it he named the following persons:
Brother Richard LOVETT
Sister Elizabeth, wife of William COCK
Sister Hannah HALL
Sister Hester HILL
Nephew Richard LOVETT, son of Richard LOVETT
(Great) Nephew Timothy TREGO, son of Timothy TREGO
Nephew Timothy TREGO
Neice Mary PARKER
Neice Elizabeth WOOTEN
Neice Ann PIERCE
Nephew Ralph COCK
Neice Elizabeth HORSBOROUGH
Cousin Robert TILBURY als TILBY of Penn
Cousin John NOBLE
Cousin John HILL
We now know that the elder Richard LOVETT was one of at least five children - himself, Timothy, Elizabeth, Hannah and Hester.
Hannah LOVETT married Francis TREGO at Amersham on 14 Aug 1676 and their son is the nephew Timothy TREGO named in the above will. He was baptised at Amersham on 13 Feb 1686/7 and had sisters Hannah (bp 1677), Frances (bp1679), Susannah (bp 1681/2) and Sarah (bp 1683). Francis TREGO died in 1687 and I suspect that Hannah married again shortly after as she is named in the will as Hannah HALL. Susannah TREGO, the dau of Francis and Hannah, married Robert TILBURY at Amersham on 16 Oct 1701 and he is mentioned in the will as a 'cousin' of the testator.
Hester LOVETT married Joseph HILL at Chalfont St Giles on 19 Nov 1691, and Ralph son of William COCKE was baptised there on 20 Dec 1696.
Nephew Richard LOVETT and neices Mary PARKER, Elizabeth WOOTEN, and Ann PIERCE are, of course, brother Richard's children. Richartd also had another daughter, Mabel, baptised at Chalfont St Giles on 6 Dec 1696, but as she is not mentioned again it is probable that she has died.