Hi, Vlad, there is no problem with these words.

However, if you want to make them into a sentence, you can add some words among them to make sense.

第一课

我前妻（太太）是朝鲜族，由于是少数民族的原因，我感觉她需要疯狂练习 n 和 ng的区别。

If you want to talk about ex-wife, you don't need to use both 前妻 and 太太, because 前妻 means ex-wife(前=ex 妻=wife), and if you change the word 疯狂 to 多加, it will sounds better, like: 我感觉她需要多加练习 n 和 ng的区别。

第一课

前妻 太太 朝鲜族
少数民族
疯狂
感觉

我需要练习 n 和 ng 区别