As I'd never read or heard this word before, I went to French Google to see if the word, as given to have come through French, is still in use there. All entries were English but for a French music group. Then I came across this entry: MW. Is it a word really much in use or did you see it for the first time too?

Merriam Webster
The Word of the Day for January 19, 2009 is:

maudlin • \MAUD-lin\ • adjective
1 : drunk enough to be emotionally silly
*2 : weakly and effusively sentimental

Example Sentence:
"Oh, please don't be maudlin," cried Monica when Mills dropped to his knees, held her hand to his tear-soaked cheek, and begged her for forgiveness.
Did you know?
The history of "maudlin" owes as much to the Bible as to the barroom. The biblical Mary Magdalene is often (though some say mistakenly) identified with the weeping sinner who washed Jesus' feet with her tears to repent for her sins. This association led to the frequent depiction of Mary Magdalene as a weeping penitent, and by the 16th century even the name "Magdalene" suggested teary emotion to many English speakers. It was then that "maudlin," an alteration of "Magdalene," appeared in the English phrase "maudlin drunk," which, as one Englishman explained in 1592, described a tearful drunken state whereby "a fellow will weepe for kindnes in the midst of his Ale and kisse you."

Not French. Just typical English sloppy pronunciation of a more complex form. The French don't have an exclusive right to sloppy pronunciation.

Is it a word really much in use or did you see it for the first time too?

It's common enough, but I haven't heard it used in a while. (The word seems just the teeniest bit old-fashioned and precious.) There's a Magdalen College at Oxford and a Magdalene College at Cambridge, and they are both pronounced /ˈmɔːdlɪn/.

The type of small, rich cake (which loomed large in the life of Proust) is so called from name of Madeleine Paulmier, 19c. Fr. pastry cook. They're really good. Nothing pathetic with those.

"Is it a word really much in use or did you see it for the first time too?"

Bran it's very common in literature if not everyday conversation though I'd guess the majority understand it; making it what I'd call a "Type-2" word

the word evokes James Joyce. link

Still: but an itch of death is in them, to tell me in my ear a maudlin tale, urge me to wreak their will.
-James Joyce, Ulysses

You are correct about the misidentification, Bran. "Mary" was a very common name, and there are several in the New Testament. The woman who washed Jesus' feet with her hair is identified in Luke as Mary of Bethany, that is, Mary the sister of Martha and Lazarus, not Mary Magdalene. Mary Magdalene is also misidentified and slandered as a prostitute so often in modern times (see Anu's statement in the AWAD email to find this same mistake being propagated...) that most people take it as fact. Nowhere in the Bible is Mary Magdalene identified as such. In fact, her role was one of a beloved disciple, and the one chosen to be the first to see Jesus risen from the dead. I'm not Catholic, but it bothers me greatly to see this false reputation continuing to be repeated and reinforced. Women have enough trouble getting respect without adding untruths!

James Joyce must have liked the word. This Google page shows it several times. I haven't finished my Ulysses yet. I fear I never will. I only read The Dubliners.

twosleepy..> A historically grown misinterpretation is not easily changed. Think of all those paintings that will have to be retitled and reviewed.

James Joyce, Ulysses ! I am still struggling along in it.
Acc'g. to your link, though, there is a book that might help me: Joysprick: an introduction to the language of James Joyce
By Anthony Burgess

But could we trust the content?

Oh good heavens! If it helps you enjoy the book it's obviously not to be trusted.