I have collected lots of information about natural and home remedies for a great many conditions - I even put an ebook together ("Collected Remedies"). No need to buy it though, as you can see the very latest remedy information I have at my website's home remedy page for free:
Another related remedie is the one for acid reflux. You might also tell your sister to take a look at this new post about heartburn, in case the problem is caused by excessive stomach acid (though odds are that it is too little stomach acid for most people):