She (Sakuntala) had heard from him (Kanva Muni) that she was the daughter of Visvamitra and that her mother was Menaka, who had left her in the forest

Expressions researched:
"she had heard from him that she was the daughter of Visvamitra and that her mother was Menaka, who had left her in the forest"

SB Canto 9

Śakuntalā informed Mahārāja Duṣmanta that although she never saw or knew her father or mother, Kaṇva Muni knew everything about her, and she had heard from him that she was the daughter of Viśvāmitra and that her mother was Menakā, who had left her in the forest.

SB 9.20.13, Translation and Purport:

Śakuntalā said: I am the daughter of Viśvāmitra. My mother, Menakā, left me in the forest. O hero, the most powerful saint Kaṇva Muni knows all about this. Now let me know, how may I serve you?

Śakuntalā informed Mahārāja Duṣmanta that although she never saw or knew her father or mother, Kaṇva Muni knew everything about her, and she had heard from him that she was the daughter of Viśvāmitra and that her mother was Menakā, who had left her in the forest.