Does anyone know why Louvain wasn't considered as a replacement for Flo? Even when they needed someone to stand-in for her onstage like when Marlene did?

She had a soprano voice, they had a more similar look than Marlene and Flo and from what I read Louvain actually did want to be on the road touring whereas it sounded like Marlene didn't want that. Actually I can't remember, was Marlene ever approached about replacing Flo permanently?