She wants to travel for Hajj with a group but without a Mahram

A woman does not have to go for Hajj unless she is able,
and having a Mahram who can accompany her is one of the prerequisites for her to be able
to go to Hajj. If it is not easy for her to find a Mahram to go for Hajj with her, then
she is not able according to Shareeah, because in Islam a woman is forbidden to
travel without a Mahram. Therefore Hajj is not obligatory for you unless you find a
Mahram. So have patience until Allaah makes it easy for you to have a Mahram with whom you
can go for Hajj. You have a valid excuse and there is no sin on you for this. As for going
with a group without a Mahram, this is not permissible because of the hadeeth narrated by
Ibn Abbaas (may Allaah be pleased with him) who said: The Prophet
(peace and
blessings of Allaah be upon him) said: No woman should travel except with a Mahram,
and no man should enter upon a woman unless her Mahram is with her. A man said,
O Messenger of Allaah, I want to go out with such-and-such an army and my wife wants
to go to Hajj. He said, Go to Hajj with her.

(Reported by
al-Bukhaari, 1729). The pilgrims used to go out from Madeenah in one
caravan like a group but still the Prophet
(peace and blessings of Allaah be upon him)
did not allow women to travel without a Mahram.

And Allaah knows best.