My sister

My sister has this strong smell, like her body odor is just terrible. She does take her showers and cleans down there and everything, but this smell just lingers on her. Anyone know what could cause her body to just have such a strong smell? I just don't want anyone to smell her one day and have her get embarrassed if they mention it. 😕 I've tried to talk to her about it, but she just won't listen.