不是名词性物主代词，是名词，意思是妈妈，例如：
1、Mothers are often the ones who provide emotional support for the family.母亲通常是家庭的情感支柱。
2、Mothers regularly go short of food to ensure their children have enough.为了保证自己的孩子吃饱饭，做母亲的经常忍饥挨饿。
3、Did you get a present for your mother?给你母亲买礼物了吗
