All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.
Whenever it is possible for you to combine between the two benefits, then do so; we mean, to be kind and dutiful to your mother and also get a job by which you can earn more money and, at the same time, seek Islamic knowledge.
We do not think that this matter is difficult in this day and age, in which the means of learning are widely available and one can learn at the hands of scholars, like on websites and through CDs and other means.
If it is not possible to combine between the two matters, then try to convince your mother of the importance of seeking knowledge and that this is something that could bring benefit for the parents as well, and to the entire nation. Abu Hurayrah, may Allah be pleased with him, narrated that the Prophet said, "When a person dies, his deeds come to an end, except for three: a continuous charity, knowledge that benefits people, and a pious child who supplicates for him." [Muslim]
If your mother is convinced, then praise be to Allah, otherwise, obedience to the parents is not required all the time; it is only required when there is a benefit for them while there is no harm on their child, as stated by the scholars.
For more benefit, please refer to fatwa 131695.
Allah knows best.