with the glances she was throwing at thir adopted children.

是的,with the glances 是介词短语作状语,修饰谓语动词 throw
with the glances 用她的眼睛瞟（他们收养的孩子）
glance 用复数是因为她瞟了不只一次
fall in love at a glance 一见钟情,就是只看一眼就对上了