The ruling on a woman traveling with women when she has no mahram (relative one may not marry)

Question: A divorced woman who is forty years old has no mahram (relative one may not marry), as she lives alone in al-Madinah al-Munawwarah; because her sons, the eldest of whom is (16) years old, live with their father in another city. This woman went to al-Makkah al-Mukarramah for 'Umrah (the lesser pilgrimage) during the blessed month of Ramadan, in a public transport bus that has a special section for women. The public transport dropped her off in front of the Haram (the sacred precinct), and after she finished her 'Umrah, she took another public transport bus to the main station outside al-Makkah al-Mukarramah, and from there she traveled to al-Madinah in public transport buses. Is she sinful for traveling, given her age and these circumstances?

Answer: If the situation is as the questioner described, then the travel mentioned is forbidden (haram), and the woman mentioned must repent to Allah for that, by feeling regret for what occurred on her part, and making a sincere resolve not to return to it; because the Prophet (peace and blessings be upon him) said: , agreed upon by al-Bukhari and Muslim, from the hadith of Ibn 'Abbas (may Allah be pleased with them both).
And Allah the Exalted said: [Surah al-Hashr: 7] And success is from Allah.