Should I say, "My mother's maiden name was Smith" or "is Smith?"

I think that one does not lose their maiden name.  They
may take the name of their spouse, but their maiden name remains intact.  The maiden
name of an individual is their name before marriage.  They do not lose their name in
marriage.  They may choose to or have to adopt the name of their spouse.  However, I do
not see this as an automatic negation of their maiden name.  Therefore, I think that the
idea would be that one still holds their maiden name in marriage and it is not an
immediate statement of the past.

With this in mind, I think
that the statement becomes that "My mother's maiden name is Smith."  In the sentence,
the mother may have adopted the spouse's married name, but her maiden name is not an
automatic denial.  This would mean that the verb in the sentence should be present tense
and not something in the past.  The verb "is" would be used to reflect the present
tense, indicating that something is still active and not in the
past.