Don't Want to Be a Concubine

In her previous life, she was a humble concubine who was poisoned by others and was a stepping stone to her success. After her rebirth, she gradually adapted to a poor but warm and happy life, but her fate took a turn for the worse. After becoming a concubine again, she faced a ruthless mother-in-law who tried her best to force her away, a brother-in-law who was greedy for her beauty and a savage maid who always wanted to replace her. Faced with a lot of open and covert attacks, how would she cope with planning the future of her family?