Mindfulness is about living in the moment, increasing awareness of what is inside and what is outside without judging self or others. There is nothing anti-biblical about it, and it does work for some people for anxiety. However, it takes a lot of work to get to the place where it can be effective. People who are in a panic attack or heightened anxiety are in a fight, flight or freeze state in which their brains function on an automatic level rather than on a cognitively semi-deliberate level. During this heightened state, it is impossible to do things like learn, and it is is very difficult to bring your own brain out of the heightened state. Sometimes people need an "external regulator" - at least while they are not in a panic state (which is when they can learn techniques such as mindfulness).
For those who have panic attacks, they need to learn these techniques when they are not in a panic state, so that when they are in the panic state, they can then start to train their brain to recall the techniques learned and gradually implement them even when panicking.
For those who have panic attacks and do not learn some self-soothing technique for regulation, they might require an external source of regulation. This could be a soothing voice of a friend, listening to calming music or nature sounds, using visualization or looking at a calming photo, etc. It might be helpful to "debrief" a panic attack with someone after it happens, and talk about what triggered it, what happens in their body, and what kinds of things they would find helpful to bring them out of it. Therapists use "exposure" until the panic reaches a peak and they learn there is no threat. If your friend's panic attacks are frequent, she should seek therapy.
