After exchanging my child system with my sister, I went crazy

In the previous life, Gu Linglong and her sister were bound to the law of time and the child-bearing system respectively. As a result, Gu Linglong's life experience was exposed and she was hunted down and killed; her sister was forced to have a child because she didn't like men, and eventually died of depression. In the next life: "Sister, do you want to switch?" "Switch!" From then on, the two sisters sang all the way. It's just that the elder sister was determined to improve her cultivation by having children, but unexpectedly someone always fell in love with her. The younger sister was cold-hearted and cold-faced, and rejected all men approaching, but there was always... a good girl who made people's heart beat. Later, the two sisters actually found that life after the exchange was really beautiful! ! ...