Views on marital age disparity in American 1910s

Setting: Chicago, 1918, MCs are upper middle class
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Search terms: earlier 1900s marriage customs, marriage age disparity history, sexual age disparity history, edwardian courtship customs, edwardian courtship, WWI marriages, early twentieth century marriage, average age of first marriage (and a lot of variants of wording), history of marriage in american 

The scene: MC A is a 16 year old girl from an affluent family. She ends up in a loving marriage with MC B, who is a 28 year-old son of family friends. One of the things that drives the story is the friction MC A encounters from her peers (other teenagers) for marrying someone so much older. However, I can't find anything that talks about how society at large would view such a match. Would they find it odd? Cute? Gross and abusive?

The questions:

1. How would upper middle class Midwestern America in the 1910s have felt about a 16 year-old girl marrying someone 12 years older than her?