Her baptism, with a birth date:

First name(s) Eliz
Last name Banyard
Year Of Birth 1800
Birth date 01 Mar 1800
Baptism year 1800
Baptism date 23 Jun 1800
Place Soham
Mother's Given Name Eliz (Late Clark)
Father's First Name Robt
County Cambridgeshire
Record set Cambridgeshire Baptisms
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I wonder if this could, just, have been her death index, the age and place are candidates:

Name: Age at Death (in years):
SCALE, ELIZABETH     49  
GRO Reference: 1849  J Quarter in THE NEWMARKET UNION  Volume 14  Page 84
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This burial confirms it:

First name(s) Elizabeth
Last name Seal
Birth year 1800
Death year 1849
Age 49
Burial year 1849
Burial date 27 May 1849
Residence otp
Parish Soham
County Cambridgeshire
Record set Cambridgeshire Burials
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While this marriage is a little early, they could have had their first births dying early:

First name(s) James
Last name Seale
Marriage year 1823
Marriage date 22 Jun 1823
Marriage place Soham
Spouse's first name(s) Elizabeth
Spouse's last name Banyard
County Cambridgeshire
Country England
Record set England Marriages 1538-1973
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