A woman having no Mahram is not obligated to perform Hajj until she has one

A: The existence of a legal Mahram with a woman, such as a father, son, brother, husband, paternal or maternal uncle, and the like, is a prerequisite for her when performing Hajj. Thus, a woman who has no Mahram is not obligated to perform Hajj until she has a Mahram. As you performed Hajj in the company of a non-Mahram relative as mentioned in the question, you committed a sin by traveling with him. Now, your Hajj is acceptable, but you have to repent and ask Allah for forgiveness for traveling without a Mahram.As for throwing the pebbles, which you mentioned in your question, that did not reach the basin (Part No. 10; Page No. 39) of throwing, if it was only one pebble, we ask Allah that He will forgive this for you.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.