Are These Our Children? 1931.
Apparently so. Mary's first film gets great reviews, and is a moral tale of the time. It is a film about 1931's New York high school crowd and was called "as old as prohibition and as new as this morning's newspaper". She is a member of a crowd of "glamourous late-hour liquor-drinking dance- hall midnight-rendezvousing" floozies who hangs out at the local "chow mein emporia".
(Available from Saul Meth's "Vintage Video")

College Humor 1933.
Although not listed as such in the credits, Mary is actually the co-star (along with Jack Oakie) in this Crosby vehicle of college life on a campus where no student seems to be under the age of 35. Mary plays "Amber", a platinum blonde with a voice that's a cross between Betty Boop and Gracie Allen (in one scene, Gracie Allen, in a cameo, slyly comments on the "nice personality" of Amber). There is one standout scene (among many) where Mary proves there is no one prettier when it comes to saying the word "no". Worth the effort to see.
(Available by rental from Eddie Brandt's "Saturday Matinee")

Flying Down To Rio 1933.
Mary plays one of Dolores Del Rio's friends in this famous musical. She has only one scene. She has only two lines. But, oh, what classic lines they are!
(Available at most major retail outlets and rental stores)

Neighbor's Wives 1933.
Also starring Vivien Oakland, critics called this film "melodramatic drivel". Drivel or not, Mary was referred to (by the very same critic) as "vivacious" (indeed). Mary's a good girl, see, and her sister-in-law tries to break up Mary's romance with a bad boy, see, so this selfsame sister-in-law, in order to save Mary from this creep's evil advances, kills this bad boy, see, and all kinds of false accusations follow, see? Well, we can't, as no copy of this film can be found anywhere!

Madame Du Barry 1934.
Dolores Del Rio plays the Mme. this time around (even Pola Negri played the part in 1920). Mary has a really small part as "Felice".

Picture Brides 1934.
Starring Dorothy Mackaill (the actress who played Mary's busybody sister-in-law in "Neighbor's Wives"), this film is about two guys who head for Brazil while on the lam from the law. Once there, they order up a couple of "wimmen" (wedding nuptuals intended) via the US mail. Mary plays a character called "Mataeo Rogers" and critics noted her performance as "standing out" from amongst the rest of the players. The "eternally ever-popular" Mae Busch is also amongst said players, although not "standing out" like Mary.

The Quitters 1934.
Here's an interesting plot: Newspaper publishing husband deserts wife and two children. Wife takes over and runs newspaper. Wife slaves to make paper a success and send at least one son through college. The young graduate becomes an ingrate and verily ruins the newspaper by using hairbrained schemes. Mother loses newspaper. Husband returns a rich man, buys the newspaper back and all live happily ever after. Where's Mary (who plays a character called "Annabelle Hibbs") in all of this? Heck if I know! Actually, Mary has but a small part in this film critics referred to as "tepid at best". Just as well.

Strictly Dynamite 1934.
This is a Jimmy Durante/Lupe Velez (now there's a pair to draw to!) vehicle in which our dear Mary has but a small inconsequential role. Next...

Desert Trail 1935.
A pretty standard John Wayne oater has Mary as the love interest. Actually, Mary doesn't figure into the plot until halfway through the film. Her role as a shopkeeper and "sis" to Paul Fix's shady character is played fairly straight. Bottom Line?  Mary was a darn good love interest for the Duke.
(Available through Noble R. Brown's "Heavenly Videos")

Adventurous Knights 1935.
Forget the plot. The film is a sort of "The Boy Friends" redux, reuiniting stars Mickey Daniels, David Sharpe, Gertrude Messinger, and Mary. (Mary doesn't appear until the final two reels). While Mickey is always fun to watch, things don't really pick up until he and Mary share some scenes. Mary plays a cabaret dancer(!) in the fictional country of Translavia. The short scenes between Mickey and Mary are the best in the film, and they truly steal the show. Particularly hilarious is a scene involving a carriage and Mickey's "Napolean" outfit.
This film proves two points: a) it's a shame more of "The Boy Friends" films are not available for viewing as the chemistry between these two truly sparkles, and b) that Mary and Mickey should have made more comedy films as a duo.
(Available by rental from Eddie Brandt's "Saturday Matinee")

Roaring Roads 1935.
The second teaming of the "Adventurous Knights" foursome, in a story about racing cars. Critics noted it was "insignificant" and the action translated to not much more than "a whimper". Still, if Mary's in it...

Smokey Smith 1935.
As rip-snorting a western as you'd ever want to see, this film shows why Bob Steele was a star (although he was wearing more lipstick than Mary). Filmed in black and white, it still has some great location scenes. And, it even has George ("Gabby") Hayes doing a wonderful turn in a straightforward role as Mary's stepfather, a ruthless outlaw gang leader. Mary does a fine job as the love interest.
(Available from Noble R. Brown's "Heavenly Video")

Queen Of The Jungle (A 12-Part Serial) 1935.
What more can be said about this ageless classic? Once voted the "worst serial ever", you have to see it to believe it. In fact, you can see it! Just url on back to the "Queen Of The Jungle" slideshow page!
(Available from Noble R. Brown's "Heavenly Video")

The Calling Of Dan Matthews 1936.
Racing cars. Dancing. Necking. Gambling. Oh, my! This is a film about decadence a- plenty in a town called Corinth (biblical implications intended). Mary plays "Kitty Marley", apparently one of a gang of "tipsy adolescents in evening dress running rampantly to hell."

Swing It, Professor 1937.
Mary must've made it back from hell okay, 'cause she plays a fairly "grown up" part in this "perky" musical. Basically a soapbox to preach that "swing and jazz music isn't all that bad" (hmm, maybe Mary didn't make it back after all - haha). The film showcases a number of swing tunes (in one montage, a sign reads: "Swing - taught in TEN easy lessons!"). Mary even gets to lip sync a song or two.
(Available by rental from Eddie Brandt's "Saturday Matinee")

Youth On Parole 1937.
Mary has a very small role in this "original" drama about two lovebirds who are falsely accused of a crime. Everything works out swell for them in the end. Doesn't it always?

King Of The Newsboys 1938.
Starring Lew Ayres, this film was called "artless" by one reviewer. Mary has but a very small role in this movie.
The plot: (If I may quote one reviewer): "It is a story of a man who loses his amour in the poorhouse, and finds her again in the penthouse. The film however, belongs in the outhouse."

I Am A Criminal 1939.
Mary's career continues to wind down as another bit part is her's to play in this film about crooks, jury tampering, and other sordid things.

On The Spot 1940.
Mary's final feature film, finishing her career with a Monogram programmer. The film stars Frankie Darro as a tough kid trying to go straight. Mary is featured a bit more prominently than her previous few films. Mantan Moreland is one of the co-stars, but the cast got only so-so reviews. Go figure.