Childhood Marriage

In Colorado a court has ruled that a 15-year-old girl could be deemed legally married by English common law, which is applicable in Colorado. (Read this article.)

Apparently the young girl's mother consented, and her mother even accompanied the girl and her 38-year-old fiance to get their marriage license.

My first reaction is that this is a horrible idea. How can she possibly be of the able mind (and body) to consent to be married to a man more than double her age when she is only 15? Upon reflection, I see a few possible arguments in favor of marriage -- maybe he has good health benefits, or maybe she is pregnant and they want to have the baby in wedlock.

The large majority of such arguments, however, are all issues that would be better resolved by his adopting her rather than marrying her! (With the exception of her pregnancy.)

At the age of 15, the world is quite a different place than it is even just a few years later in your early 20s. It may seem that young girls are "older and older" at younger ages, but (aside from the pregnancy case), what is the big rush to marriage?