Is it permissible for me to perform Hajj without a mahram? And will my performance of Hajj be counted as the obligatory Hajj of an adult if I perform it with a mahram, knowing that I have not yet reached puberty?

We have previously explained the permissibility of a woman traveling for the obligatory Hajj with a safe company, provided there is no fear of temptation. If you are twenty years old, you are an adult, and all that is incumbent upon women is incumbent upon you, and all that is forbidden to them is forbidden to you. If you perform Hajj, the obligation of Hajj will be lifted from you. A non-adult female who is desired is considered like an adult. Whoever performs Hajj before reaching puberty, that Hajj does not suffice for the Hajj of Islam, but they will receive the reward for Hajj. A child is rewarded for acts of obedience, and sins are not recorded against them, by consensus.