The database structure really depends on the requirements of your application. But based on my limited knowledge I'd probably just do it with two tables.
Family Table
---------------------
FamilyID
FamilyManager
FamilyName
FamilyPreQuestionnaire
FamilyPostQuestionnaire
...
Questionnaire Table
----------------------------
QuestionnaireID
QuestionnaireTimestamp
QuestionnaireQ1
QuestionnaireA1
QuestionnaireQ2
QuestionnaireA2
...
You could use the same questionnaire table for both pre and post just put the associated ID in the Family table when they fill it out.