Although breast cancer is one disease, there are many factors that play a part when judging each person's treatment and chances of getting cured, which I assume is what you mean by "making it". Only the person's doctors can give accurate information about how the situation is for that particular person. I will provide you with some general information and hope that you may find out more from your mum and her doctors.
One important factor in breast cancer relates to whether the cancer cells are only to be found in the breast itself or if they have moved to other parts of the body. As you may know, the main reason why cancer can be serious is because the cancer cells can break off from the main tumour and settle down in other parts of the body. The term we use when talking about the extent of a breast cancer in this way is "stages". Breast cancer is divided into 4 stages depending on the size of the cancer lump in the breast and if cancer cells have settled down anywhere else.
The treatment of breast cancer can therefore be very different from one person to another, depending on what stage the cancer is in. The treatment can also be different if the cancer is stimulated by hormones. Hormones are substances that occur naturally in our bodies where they control the growth and activity of normal cells. Although they do not usually affect cancer cells, they can affect some breast cancers. This means that drugs or treatments that block the effects of these hormones can be used as a treatment for some types of breast cancer. As said before, only your mum's doctors will know which treatment is best for your mum.
Luckily, there are lots of research going on and very good treatments available for breast cancer, often by using a combination of several treatments like your mum is having. The fact that your mum is having more than one treatment does not mean that her cancer is bad. It is very common to give several different treatments for breast cancer as they work together and treat the cancer in different ways. Even when the doctors think that they have managed to remove the whole cancer lump in the breast, they usually give other treatments as well, trying to make sure that any possible remaining cancer cells are being killed.
In general, if the cancer is diagnosed at an earlier stage, people have a better chance of being cured. It is very positive though, that even in those cases where a cancer can not be cured, people can live with breast cancer for many, many years - much longer than what is the case with many other cancer types if they are not cured.
Maybe one of the more difficult things for you now is the fact that you don't seem to talk openly about this in the family. It might of course be that your mum is not too sure about what will happen, it may be very uncertain before her treatment is over or she may not have asked the doctors about these questions. It is of course up to your mum what she wants to ask the doctors about and she can also decide what she wants to share with you. Maybe you could tell your mum about what's on your mind, as many parents underestimate the concern that their children have and the type of information they want to know. Although cancer can be very scary and difficult to talk about, it is usually better to talk openly about the thoughts and fears that we have. We so often see how family members try to protect each other by not talking about it, whereas in reality everybody is thinking about the same things anyway.
What parents want most of all is to protect their children from difficult things in life and it can be easy to think that the best is not talking about the cancer and the treatment. Many parents think that if they don't talk about it, it is easier for the children to keep it at a distance. We know that it often works the opposite way and that things are easier to deal with if they are out in the open and not bottled up inside us. I hope you will get the answers you are looking for and that your mum will be fine.