I found the birth of your great grandmother, Laura Jane Wade nee Greatorex by trying just "Laura 1848 to 1848" in the India births search. She'd never have shown up otherwise:

Name: Laura Jane Grratonox
Gender: Female
Baptism/Christening Date: 06 Jan 1848
Baptism/Christening Place: Madras, Madras, India
Birth Date: 01 Nov 1847
Birthplace:
Death Date:
Name Note:
Race:
Father's Name: John Thomas Grratonox
Father's Birthplace:
Father's Age:
Mother's Name: Jane Maria
Mother's Birthplace:
Mother's Age:
Indexing Project (Batch) Number: C00068-0
System Origin: India-EASy
Source Film Number: 521846
Reference Number: v 27 p 12

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Name: Jane Maria Greatorex
Gender: Female
Burial Date: 26 May 1865
Burial Place: Madras, Madras, India
Death Date: 25 May 1865
Death Place:
Age: 41
Birth Date: 1824
Birthplace:
Occupation:
Race:
Marital Status: Married
Spouse's Name: John Thomas Greatorex
Father's Name:
Father's Birthplace:
Mother's Name:
Mother's Birthplace:
Indexing Project (Batch) Number: B00202-3
System Origin: India-EASy
Source Film Number: 521853
Reference Number:

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Groom's Name: John Thomas Greatorex
Groom's Birth Date: 1825
Groom's Birthplace:
Groom's Age: 41
Bride's Name: Mary Laura Recontre
Bride's Birth Date: 1830
Bride's Birthplace:
Bride's Age: 36
Marriage Date: 04 Jun 1866
Marriage Place: Madras, Madras, India
Groom's Father's Name: John Greatorex
Groom's Mother's Name:
Bride's Father's Name: Theodore Recontre
Bride's Mother's Name:
Groom's Race:
Groom's Marital Status: Widowed
Groom's Previous Wife's Name:
Bride's Race:
Bride's Marital Status:
Bride's Previous Husband's Name:
Indexing Project (Batch) Number: M00550-0
System Origin: India-EASy
Source Film Number: 521854
Reference Number:

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Name: John Thomas Greatorex
Gender: Male
Burial Date: 08 Mar 1906
Burial Place: Madras, Madras, India
Death Date: 07 Mar 1906
Death Place:
Age: 82
Birth Date: 1824
Birthplace:
Occupation:
Race:
Marital Status: Unknown
Spouse's Name:
Father's Name:
Father's Birthplace:
Mother's Name:
Mother's Birthplace:
Indexing Project (Batch) Number: B00208-8
System Origin: India-EASy
Source Film Number: 527471
Reference Number:

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I can't find a maiden name for Jane Maria / Maria Jane (she uses both in the birth entries of Laura's siblings)

And I can't find a death entry for Mary Laura Greatorex alias Recontre.

Jean C