It is not an admission of weakness but the demonstration of love and support. Any sorrow, any loss, any mourning leaves an imprint on the healthiest of personalities. The pieces that we allowed to attach to the deceased, leave gaping holes in all of us. Children are never replacements for a dead sibling. Children are never substitute adults or surrogate relatives.
Children are never friends or lovers or companions or confidants.
It is difficult enough for children to lose a loved one. We should not deprive them of their childhood either. We should never give stories and fantasy and fairy tales as explanations for the mystery of death. In truth, good people do die young and so do bad people. Any of these unhealthy explanations can create fear, doubt, guilt, and encourage flights of fancy that are far more bizarre than reality.