Table: t_1835_louisa_marriage
Columns: year_of_marriage
name
her_age
his_age
of_children

Question: What is the mean year of marriage when her age was more than 19 and his age was 30?
SQL: SELECT AVG("year_of_marriage") FROM t_1835_louisa_marriage WHERE "her_age" > 19 AND "his_age" = 30

Question: What is the lowest figure for her age when the year of marriage is before 1853, the number of children is less than 8, and the bride was Eliza Maria Partridge?
SQL: SELECT MIN("her_age") FROM t_1835_louisa_marriage WHERE "year_of_marriage" < 1853 AND "of_children" < 8 AND "name" = 'eliza maria partridge'

Question: What is the total number of her age figures where his age is less than 33, the bride was diontha walker, and the number of children was less than 0?
SQL: SELECT SUM("her_age") FROM t_1835_louisa_marriage WHERE "his_age" < 33 AND "name" = 'diontha walker' AND "of_children" < 0