Sometimes it happens because her tummy doesn't feel good. Back in my country, we have the so called baby masseuse. Check her ear and body, does it feel cold? Body should be warm when it is touched. If it cold, there's something. Why don't you give it a try? I always massage my baby tummy. This is what I do. Buy Vicks balm, rub it on the parts of body where it feels cold. For the tummy, add few drops of oil to make it easy to massage. You rub your palm from the sides of the tummy to the center of tummy( not navel, above that). Do it as if you are making snowman, you know it means like you want to gather something to the center of it, not just patting. Do it like 5 times from each side. Imagine her tummy as a clock, you massage from number 12, 1.30, 3, 4.30, 6, 7.30 and so on to the center of the clock. For her back, you can coin her. It is called gua sha or coining. You can google what it is and watch the video on youtube how. The coining will left purple marks. But if she is not sick,the coins will left no mark. Usually after I do it, my son eats a lot and sleep soundly. Good luck.