Looking up...
Elle est ma compagne de voyage.
She is my travel companion.
A female companion, especially a female partner or friend
Ma compagne et moi avons passé un week-end agréable.
My companion and I had a pleasant weekend.
Often used to refer to a female partner in a romantic relationship.
'Compagne' is specifically feminine, while 'compagnon' is masculine.
From Old French 'compainne', from Latin 'companio' meaning 'companion'
In modern French, 'compagne' is often used to refer to a female partner in a romantic relationship, while 'compagnon' is used for a male partner.