I was not at all surprised to read that "Look for the Silver Lining" is a highly sanitized bio-pic. After all, Hollywood has a long, long history of making biographies that omit all the wicked stuff in favor of glitz and entertainment. A couple such films that come to mind are "Night and Day" (which bears little similarity to the life of Cole Porter...especially since he was gay) and "Love Me or Leave Me" (which makes Ruth Etting seem almost as sweet as Mary Poppins). To Hollywood, history was just a starting point in 1930s-50s films and a little embellishment (or A LOT) was just part of making the story marketable. Because of this, it's usually bad if the viewer thinks this is a history lesson! In fact, a film of the era that accurately tells the story is the exception rather than the rule. So, if you want to learn about the life of Marilyn Miller, I suggest you read a biography or skim the internet!
This film begins with Marilyn (June Haver) an established star about to do a new stage production. She seems a bit under the weather...and the film soon flashes back to her youth before she became famous. You then see her life unfold...or at least the studio's version of her life. It's all very slick, very entertaining and filled with nice scenes and very nice song and dance numbers...though as I said above, it's terribly sanitized and inoffensive. I also thought a couple scenes were overdone (such as when Mr. Miller had the mumps...talk about overacting!) and the sledgehammer symbolism with the broken elephant was just too much. Still, inoffensive and enjoyable provided you don't care about the many liberties the story took on the true life of Ms. Miller. This is especially true of the final portion--which bore no similarities to Miller's life at all.