All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
First of all, we ask Allaah to cure your mother and enable you to meet her, and we ask Him to facilitate your affairs and provide you in abundance.
We have already issued Fataawa 83940 and 86565 clarifying that it is not permissible for a woman to travel without a Mahram, and this is in order to protect her from reasons of temptation, and she is not permitted to travel without a Mahram except for a necessity like her travelling from a non-Muslim country when fearing to doubt her religion there and the like, but it is not permissible for her to travel without a Mahram just because she is a new Muslim.
As regards visiting your mother, then this is not a necessity, because you may keep ties with her without visiting her, especially with the availability of modern means of communication, and you may even see each other despite the long distance between you and her; for more benefit, please refer to Fatwa 83403.
However, if a person fears Allaah, Allaah will facilitate his affairs. It might be that if you do not travel without a Mahram, Allaah may remove the obstacles which are a hindrance to your husband travelling with you. Allaah Says (what means) {… And whosoever fears Allaah and keeps his duty to Him, He will make a way for him to get out (from every difficulty). And He will provide him from (sources) he never could imagine.}[Quran 65:2-3] Allaah also Says (what means) {And whoever fears Allaah -- He will make for him of his matter ease.}[Quran 65:4]
Furthermore, Imaam Ahmad reported that the Prophet said: "You do not leave anything out of fear of Allaah, except that Allaah will compensate you with something better."
Finally, we advise you to earnestly supplicate Allaah to cure your mother, and supplicate Him to provide you with beneficial knowledge and lawful provision and deeds that are accepted.
Allaah Knows best.