Where do you think Lucy was born? On the 1861 census she states her age as 24 and her birthplace as Isleworth (it is quite common on censuses for people to sometimes state their place of birth as the same as the place they are living and then contradict themselves on later censuses). On the 1871 census Lucy states her age as 35 and her place of birth as Longford Berkshire.
Does Lucy appear on later censuses and if so where does she state then as her place of birth?
On the 1851 census there are 6 Lucy Lovegroves, 2 of whom are wives, plus 3 daughters and one servant all in Berkshire, Buckinghamshire or Oxfordshire. One is Louisa Lucy and only aged two. Of the other available Lucys they are
Lucy aged 13 born Aylesbury Buckinghamshire in Aylesbury.
Lucy aged 21 born Pishill Oxfordshire in Oxfordshire.
Lucy aged 19 born Remenham Berkshire in Oxfordshire.
What details about her father does Lucy give on her marriage? That might help place her on the 1841 census. There is a possibility for her in Longcott Berkshire on the 1841 census.
Are you aware there is a one name study of the surname Lovegrove? The researcher is likely to hold detailed information on many Lovegrove families and might be able to narrow down which Lucy Lovegrove it might be.
http://www.one-name.org/cgibin/surname.cgi?find=lovegrove&Go=SearchRegards
Valda