Who are the two concubines of Prime Minister Liu?

Prime Minister Liu has two daughters-in-law, a wife and a concubine to be exact. In the TV series Prime Minister Liu, Liu Yong first married the daughter of six princes, played by Deng Jie, but the daughter of six princes was barren. In ancient times, there were three unfilial girls. She asked Liu Yong to choose one of the two maids at home. Liu Yong chose thinner purples as his concubine and gave birth to a son for Liu Yong.