Welcome to our TNBC Foundation family. I am very sorry you have need to be here but we will try to help you, as best we can.
The first thing I would suggest you do is try to take a deep breath and gather your strength. There is a very good chance Mom can get through this o.k.
It is very important, in my unprofessional view (I am a volunteer patient advocate and do not give medical advice) to make sure that Mom is in the hands of a Breast Medical Oncologist who is familiar with TNBC. I am told that Dr. John Cole may be a good resource for Mom. He is at Oschner Clinic in New Orleans I believe.
The other cancer center I would suggest is MD Anderson Cancer Center in Houston Texas. I think highly of a Dr. Ana Maria Gonzalez-Angulo and MD Anderson is ranked the number one cancer center in the U.S.
I am a great believer in second opinions and it may also be especially important to get a second opinion on Mom's pathology report to make certain the results are correct. Ask if FISH was used to determine if HER2/neu was truly negative. About 15-20% of the time the IHC results are incorrect and if so the patient misses the opportunity to take a drug called Herceptin which can help if the HER2/neu is + instead of -.
I am going to send you a PM (Private Message) with my contact information. I would be happy to talk with you.
As far as quitting school, I am going to give you what some may consider a convoluted answer. I would be guided by what your mother would like you to do and also if you do stay in school you and your twin should make as much effort as possible to be as supportive of mom as possible.
There is a good chance Mom will go through a course of chemotherapy and if you or your twin can go with her to her infusions I think that would be important, supportive time.
wishing you and your mom the best of luck.