My co worker have a really really bad BO

My co worker have a really bad body oder, she is overall very clean and hygienic but her strong BO makes it very difficult to sit close to her in meetings or during lunch breaks.
She is not only my coworker but we were in college together and are friends as well.
Its too much that after she uses the bathroom, bathroom smells like her BO.
How do i tell her to wear deo or perfume even.