Aww, that lower back pain is really tough, lalo na pag busy ka with the kids! A few of us moms swear by proper posture, warm compresses, at stretching, pero honestly, kung tumatagal na yan or sobrang sakit, better have it checked with your doctor para ma-rule out kung may underlying issue. In the meantime, try to avoid heavy lifting kung pwede, rest when you can, at make sure your sleeping position is supportive.