I find out :
Marie Louise is born Perez Orego . She married in 1963 Comte Antoine de Clermont Tonnerre Son of Thierry de Clermont Tonnerre and Leonie de Rohan Chabot.
They divorced and Comte Antoine married a second time.
In fact she is not Chermont Tonnerre anymore, but when you started bussiness with your surname you may keep it for commercial reasons. As Diane von Furstenberg.