Kids and anxiety

So I have a 6 year old who is having some anxiety which causes chest pain ( nothing is wrong with her heart) we’ve been to the doctors and they have said anxiety or acid reflux and to find the triggers and to start therapy. Wel therapy is still about 3 weeks away that’s the soonest we could get in. Anxiety is something that runs in our family I’m medicated for it but want to try to avoid medication on my little one if we can find a relief. I don’t really know how to help ease it since I don’t even know how to ease my own any tips or advice I’ve also read about magnesium deficiency could that be a cause is there a kind I could try? I’m pretty much up for anything at this point. Also not sure if it’s returning to school and having to wear a mask all day I’m just at a loss here