Sure, here is the translation:
Soon, my niece reached the age to attend primary school.
At the dinner table, my sister-in-law instructed me to have my niece attend the school where I was teaching.
"Let Xuanxuan go to your school! You'll be responsible for all her schooling issues from now on!"
"This can be counted as your accommodation fee for living at home! If you do well, I'll reluctantly introduce you to some good cousins."