No pleading subsequent to the petition for a deprived child proceeding is required and the filing of any motion or pleading shall not delay the holding of the adjudicatory hearing. A petition may be amended by order of the Court at any time before an order of adjudication has been made; provided, that the Court shall grant the parties such additional time to prepare as may be required to insure a full and fair hearing. A petition shall be deemed to have been amended to conform to the proof where the proof does not change the substance of the act, omission or circumstance alleged. However, the Court shall not amend the adjudicatory category prayed for in the petition.