Contrary to the other answers, I think that you can tell your family member that you think her beliefs are wrong and probably even get her to reconsider her stance on some of them. That is not to say it will be simple/guaranteed though.

## Use empathy before logic ##

Most beliefs of this nature have an emotional root, meaning that they will just tune out, giving an excuse (such as: *you have a very linear and mathsy way of thinking, therefore you can't possibly understand my "facts"*) when someone suddenly points out some otherwise perfectly sound logic.

To get past this emotional block, it is essential that you first connect with them emotionally, using empathy to show that you are listening to what they say. Try to find an underlying emotion that is the seed to this belief (such as a fear of being helpless in terms of illness where your only option is to blindly trust a doctor which as she has seen, is still no guarantee). This may not be your family member's reasoning, but it is a common fear that leads to people going down the same path as her as it is more comforting to feel that you are able to do something yourself that you 'understand' than to do what is actually best (i.e. go to the doctor and do what they say). Note that there is a fine line between understanding and being empathetic of the reason, and presuming or shallowly blaming their belief on something. Saying something like "ooh, you only think that because of X" will have the opposite effect, and instead will leave them feeling as though you have rudely undermined their worries rather than shown empathy. Try to only mention reasons that they themselves have acknowledged, and phrase it in a way that validates the reason, rather than using it to blame their misconstrued ideas. If you can show that you are empathetic and understanding of the fear, it will breach the emotional block and then she will be able to properly listen to your logic.

## It takes time ##

Although it would be lovely, you are not going to change anyone's view of the world and help them reach a deeper understanding of how things are in just one day. It is important that you understand it takes a long time for these things to happen. Forcing someone to talk about a subject they don't want to engage in will only be counterproductive; you need to wait for when they are happy to talk about it and try to stay open and willing to go into conversations with them.

## Consider introducing her to proper studies, research papers and the process they go through before its accepted by the scientific community ##

I know it's not so much IPS, but this is the big one that helped bring my cousin to critically look at conspiracies he would have previously followed. You mentioned you are a physicist so I am assuming you are somewhat active in the scientific community and know that the people who are the most critical of scientists are **other** scientists. As it is not practical to deeply study and understand every new topic in science, it is important to understand the process these things go through before they are accepted; and even after they are accepted they still get analysed and verified over and over again. If you can get her to understand this, and also how to tell the difference between shallow pseudoscience studies and real ones then she will be able to do your job for you and may re-look at a lot of the things she currently believes herself. Obviously this is not the first thing you should do and would take a considerable amount of time and effort, not to mention she may just reject the effort flat out. Just keep this in mind for later on if she has reacted well to the earlier and more specific explanations where you were focusing on being empathetic.

## On avoiding conflict ##

There is no guarantee that you will never raise any conflict when discussing these things. But so long as you are kind and remain calm/rational yourself they should not be lasting. That being said, there are some things you should avoid:

 - Don't force the conversation on her
 - Don't force a viewpoint on her
 - Don't be disrespectful or condescending (some beliefs may be ludicrous, but saying so is one of the worst things you can do)
 - Don't be impatient or get frustrated
 - Don't be hypocritical (if you want her to listen to you, you should also be open to listening to her)