You might wanna grab a good book on db design theory. What you should do is create a table called something like classification and insert three rows:
id class
1 MOTHER
2 FATHER
3 INDIVIDUAL
And then use those numbers in the main table to denote which is which in a field called, oddly enough, classification. Make this field reference the classification.id field like so:
select * from
maintable m,
join
classification c
on (m.classification = c.id)
where
c.class = 'MOTHER';