Marydoll
Is your friend by any chance taking a particular medication, that can cause it?
I once had a pair of favourite shoes, which I hadn't realised, that in hot weather made my feet rather smelly.
I was going into classes round the school, when one colleague apologised for the smell in her class, mentioning a particular child. I realised it was my feet! 
I said nothing, hurriedly rushed off and those shoes went straight into the bin, replaced by an old pair in my room! I was mortified.
We were visiting my son recently, and my husband was wearing sandals. He was sitting next to me on the sofa, and I kept glaring at him and 'subtly' trying to mime that he should move his feet out of the way, as people were eating from snacks on the table, and the pong was distracting from the food.
When my DIL came to clear the snacks away, she commented on the dreadful smell . . . . . .of the Cheesy Doritos
.