She couldn't pretend to not know her niece in public. If she did, that would make it seem like she had a guilty conscience.
However, when He Yan arrived in front of Jian Yiling, she realized that Jian Yiling had come alone. She didn't come with her parents or anyone else.
"Yiling, why did you come by yourself?" Jian Yummin asked her out of curiosity.
"I came to look around," Jian Yiling replied.
Jian Yiling didn't know why that person wanted to meet her today. Furthermore, she didn't know why the meeting was on such an occasion as well.
She didn't come here for any other reason. As such, she had decided to take a look around.
"Where is your mother? Why did she let you come by yourself?" Jian Yumin asked in a hurry. His burrows were furrowed. If someone didn't know better, they'd assume that he was angry.
In Jian Yumin's mind, Jian Yiling was still a child. She could get lost if she went out by herself.