She won't have any trouble at the elementary school level.
She shouldn't have any difficulty studying in a class with elementary school age kids.
ーShe won't have any trouble at the elementary school level.
「彼女は小学生レベルで問題ないと思うよ。」
won't have any troubles at ... で「…で問題ないだろう」と言えます。
ーShe shouldn't have any difficulty studying in a class with elementary school age kids.
「彼女なら小学生のクラスで学んでも困らないわよ。」
shouldn't have any difficulty studying で「学ぶことに困らないだろう」と言えます。
ご参考まで！
カナダ 
