You will be on the right track by encouraging her. Do not pay an inordinate amount of attention to the matter, and in particular do not broach it yourself. If your daughter raises it, express curiosity and interest in her perceptions, and basically 'sound her out'. Try to stay away from offering opinions or reassurances. Your careful listening will be encouragement enough. Sometimes we think that if we listen seriously to our children's concerns, and then don't counter them with reassurances, we'll only be strengthening the point of view that worries us. In reality, sensitive and attentive listening is, most of the time, more helpful than a thousand words of reassurance.