No, it wasn't. In the TV series Joy of Life, Liu Ruyu was played by actor Zhao Ke, and Yi Guipin was played by actor Sui Junbo. It could be seen that they were played by different actors. Although they played cousins in the drama, they were not the same person.

Yi Guipin was played by Deng Tongtian, and Liu Ruyu was played by Zhao Ke.
Yi Guipin and Liu Ruyu were cousins.
The characters in Joy of Life, Liu Ruyu and Yi Guipin, were cousins. Yi Guipin was Liu Ruyu's cousin and also Fan Xian's " stepmother " Second Concubine. Yi Guipin was a beauty of the Liu family. She was taken into the Qing Emperor's harem and gave birth to the Third Prince, Li Chengmin. Even though the Third Prince had not been considered to be the Crown Prince before the Crown Prince and Second Prince rebelled, Yi Guipin was deeply loved by the Qing Emperor because she was good at pandering to the Qing Emperor's preferences and had no ambitions. Yi Guipin's appearance revealed the depth of Liu Ruyu's background and played a key role in the play, becoming Fan Xian's greatest help in the Palace. Thus, Liu Ruyu and Yi Guipin were cousins.
No, Lady Liu was Fan Xian's mother, played by Zhao Ke, and Yi Guipin was Lin Wan 'er's mother, played by Sui Junbo. The two of them were cousins in the play. Yi Guipin, played by Sui Junbo, appeared in the second season. Her nobility from the inside out instantly conquered the hearts of all the audience. Sui Junbo's ancient costume had an amazing similarity with Zhao Ke, which not only made the audience's eyes light up, but also cleverly fit the relationship between Yi Guipin and Aunt Liu.
In Joy of Life, Yi Guipin seemed to be an upright and kind character. She was very fond of Fan Xian and had no ambition. Her son eventually became the emperor. Although there was no specific description of Yi Guipin's actions or personality, from the relevant information, Yi Guipin and Fan Xian had deep feelings. She was favored and trusted by the Qing Emperor and became the empress dowager. Therefore, Yi Guipin could be considered a good person.
In Joy of Life, Yi Guipin seemed to be an upright and kind character. She was very fond of Fan Xian and had no ambition. Her son eventually became the emperor. Although there was no specific description of Yi Guipin's actions or personality, from the relevant information, Yi Guipin and Fan Xian had deep feelings. She was favored and trusted by the Qing Emperor and became the empress dowager. Therefore, Yi Guipin could be considered a good person.
In Joy of Life, Yi Guipin was a concubine favored by the Qing Emperor. She was very fond of Fan Xian and had no ambition. Her son, the Third Prince, eventually became the Emperor. Although there was no specific description of Yi Guiping's behavior or personality, from the relevant information, Yi Guiping seemed to be an upright and kind character in the play and had deep feelings for Fan Xian. Therefore, Yi Guipin could be considered a good person. However, there was no information about Yi Guipin's ending in the play, so it was impossible to determine her final fate.
In Joy of Life, Yi Guipin seemed to be an upright and kind character. She was very fond of Fan Xian and had no ambition. Her son eventually became the emperor. Although there was no specific description of Yi Guipin's actions or personality, from the information, Yi Guipin and Fan Xian had deep feelings and were favored and trusted by the Qing Emperor. Therefore, Yi Guipin could be considered a good person.
Yi Guipin, who was in the Qing Yu Nian, seemed to be an upright and kind character in the play. She was very fond of Fan Xian and had no ambition. Her son eventually became the emperor. Although there was no specific description of Yi Guipin's actions or personality, from the information, Yi Guipin and Fan Xian had deep feelings and were favored and trusted by the Qing Emperor. Therefore, Yi Guipin could be considered a good person.
In Joy of Life, Yi Guipin seemed to be an upright and kind character. She was very fond of Fan Xian and had no ambition. Her son eventually became the emperor. Although there was no specific description of Yi Guipin's actions or personality, from the relevant information, Yi Guipin and Fan Xian had deep feelings. She was favored and trusted by the Qing Emperor and became the empress dowager. Therefore, Yi Guipin could be considered a good person.