It would be much easier if you had your table structure properly normalized instead of having repeating fields.
But to use what you've got, you would need to call Show2ndMember in the form's On Current event as well as in the After Update event. But you need to modify Show2ndMember to have the If instead of in the after update event:
Code:
Private Sub listMemberType_AfterUpdate()
Show2ndMember
End Sub
Code:
Private Sub Show2ndMember()
Dim blnTF As Boolean
If Me.listMemberType.Value Like "*FAMILY" Then
blnTF = True
End If
Me.lab2ndMember.Visible = blnTF
Me.labSalutation2.Visible = blnTF
Me.comSalutation2.Visible = blnTF
Me.labFirstName2.Visible = blnTF
Me.txtFirstName2.Visible = blnTF
Me.labLastName2.Visible = blnTF
Me.txtLastName2.Visible = blnTF
Me.labBirthDate2.Visible = blnTF
Me.txtBirthDate2.Visible = blnTF
End Sub