The Matchmaker is responsible for arranging marriages and evaluating potential brides and grooms. Thus, she holds a great deal of influence, as women of the time are believed to uphold family honor only by marrying and bearing children (especially boys).
She is described by one woman as being very impatient, and she also seems to be very strict and harsh. In the second film, Ling describes her as also being "smug and snooty".
The Matchmaker appears at the beginning of the film. She calls Mulan to be the first of the candidates, and immediately scolds the girl for speaking without permission (which causes Grandmother Fa to remark on the woman's harsh attitude).
Inside, she puts Mulan through a series of evaluations. She first notes that Mulan is "too skinny", which is supposedly not good for bearing sons. The Matchmaker then has Mulan recite "The Final Admonition", but becomes suspicious that Mulan is cheating when Mulan falters.
Finally, the Matchmaker has Mulan pour tea, while the Matchmaker speaks of Mulan's future role in her in-laws' home - poised, dignified, and refined, but silent (women were not allowed to speak in their in-laws' presence, nor in the presence of men such as husbands and fathers, as Chi-Fu reveals later). At this point, Cri-Kee, who was in a cage hidden under Mulan's dress, escapes into the cup of tea that the Matchmaker was about to drink. Mulan attempts to retrieve the cup to stop the Matchmaker from consuming the cricket.
Unfortunately, this results in a series of accidents, culminating in Mulan pouring tea on the Matchmaker in an attempt to douse the fire that is burning the Matchmaker's dress. Mulan quickly heads outside. The Matchmaker openly berates Mulan in front of the crowd, noting that though Mulan looks like a bride, she would never bring honor to her family through becoming a servile wife.
The Matchmaker is not seen for the rest of the film after Shan Yu's death at the hands of Mulan. She presumably brings honor to Mulan when she becomes the hero of China but it is unknown if she would respected Mulan.
The Matchmaker makes a minor appearance in the sequel. In her appearance, Mulan and Shang's friends, Yao, Ling, and Chien Po visit her in an attempt to find brides for themselves. But, just like Mulan's visit at the beginning of the first film, the mens' visit to the Matchmaker ends in disaster as calamity. The Matchmaker throws out the trio (literally) and throws a pot at Ling's head, and claims that they'll never be able to find brides. After that she isn't seen for the rest of the film.