It was an arranged marriage approved by her father. Paedophilia seldom is about actual marriage or one arranged by a loving concerned father protecting his daughter from exploitation. And note that Muhammad did not immediately have relations until she came of age, that is had menses. We find similar rules and discussions in Christian theology about Mary who is usually presented as very young just having passed Jewish age of maturity of 11 or 12. Are you as a pious Christian willing to accuse God or the angel Gabriel of being paedophilia per your definition.