and as yet I have not found a birth record for her, only her baptism.

Its pre 1837 - so this is likely to be the best / only record

Year: 1826
Month: Oct
Day: 8
Parents_Surname: RUCK
Child_Forenames: Letitia
Fathers_Forenames: John
Mothers_Forenames: Susannah
Mothers_Surname:
Residence: Yorkley
Occupation: Labourer
Officiating_Minister: H[enr]y Poole Minister
Event: Baptism
Memoranda:
Notes:
Register_Reference: P245 IN 1/9
Page_Number: 34
Parish_Chapel: Parkend

links to several threads including

http://www.forum.forest-of-dean.net/index.php?id=31629