proved a lenient teacher

English as a Second Language English Vocabulary, Grammar and Idioms
1

Paradoxically, Sharmeen, who had been a strict to her children, proved a lenient teacher to her student.

Is the sentence correct?

2

No.

“… who had been a strict mother to her children…”
“… who had been a strict disciplinarian with her children…”
“… who had been strict with her children…”