After Rebirth, the Eldest Sister Rescued the Crown Princess First

My sister and I were on our way to a banquet when the carriage accidentally knocked down a beggar. My sister-in-law was afraid of losing time, so she advised me not to cause trouble. I felt pity for the beggar, so I took her to the medical center for treatment. As a result, I missed the opportunity to meet the children of the aristocratic family. However, the eldest sister shined at the banquet and was appreciated by Mrs. Zhongyuan Bo. Unexpectedly, the beggar turned out to be the princess of the dynasty. In order to reward my kindness, the queen not only rewarded me with a thousand taels of gold, but also allowed me to come to the palace as a companion, which attracted the envy of everyone in the capital. Later, when the princess was named the Crown Princess, I was still a popular figure around her, as good as the princess sisters. Many children from high-ranking families came to ask for her hand in marriage, and eventually I was given the marriage to the prince. After marrying into the Earl's Mansion, the eldest sister discovered that the young lord was terminally ill, and the marriage was purely for happiness. The day my sister-in-law became a widow, I had just made the decision to marry her. She was resentful and secretly poisoned my tea in the name of congratulations. When I opened my eyes again, I went back to the day of the banquet. This time, the eldest sister was the first to help the princess who fell to the ground. Little did he know, this was the beginning of her nightmare.