In general all types of visas may be revoked or cancelled if there is a change of circumstances such as end of a relationship, no sponsor or deception and/or misrepresentation used. This also applies to a Child visa, which can be revoked or cancelled if the sponsor/parent is no longer acting as a sponsor.

Original Source: https://www.quora.com/Can-a-child-visa-be-cancelled/answer/My-Legal-Services-1