Whilst it may be the case that traumas can be forgotten and then later remembered, it also may happen that apparent memories and beliefs about past events, even when experienced with conviction, can turn out to be false. Immense damage can occur through investing perceived memory with undue certainty. Human cognition, perception and memory are all flimsy functions that are prone to error.
This subject is extremely complex. The most important point is that many problems arise when beliefs and illusions of knowing are applied inappropriately, or when we adopt an unwarranted confidence in our perceptions and assumptions. Since the state of not knowing, of feeling uncertain and confused, can be highly aversive, we tend to fall back on an assumption of knowing that may be unsound. Beliefs, of whatever kind, are often treacherous - and can block further enquiry. It may be better, as far as possible, to replace beliefs with working hypotheses that can always be revised in the light of emerging evidence.
Of course, none of this negates the reality that children can be abused by adults or older siblings - and sometimes the abuse can be of a kind that violently assaults our preferred beliefs and perceptions concerning the nature of humanity and society.
This page will be developed further.
Books on the illusions of memory:
Brand, N. 2007 Fractured Families: The untold anguish of the falsely accused. [BFMS.Bradford on Avon.]
Mollon, P. 2002. Remembering Trauma. A Psychotherapists' Guide to Memory and Illusion. 2nd Edition. [Whurr/Wiley. London]
Schacter, D.L. 2001 How the Mind Forgets and Remembers. The Seven Sins of Memory. [Souvenir Press. London]