How many characters imprinted on girl-children other than Jacob, Real Fan? None? Then how do you know what was going through Stephenie Meyer's mind when she chose to link Jacob the Indian to a child?
In fact, how do you know she didn't make an unconscious association based on race? Even she may not have been aware what she was thinking.
I've talked about aversive racism before. The idea is that even people who insist that they're "colorblind," that they believe all races are equal, are unconsciously prejudiced. When they're tested, they generally favor whites over minorities. They generally think blacks are less qualified for jobs, more likely to commit crimes, less attractive and more unlikable.
Again, these are people who insist that they view whites and blacks as equals. The studies demonstrate that what they consciously say doesn't match what they unconsciously think and feel.
Although researchers usually don't test attitudes toward Indians, I've experienced enough to know what most people think. To confirm this, consider the tidbit I posted in The Harm of Native Stereotyping: Facts and Evidence:
Wilson asked participants where they got their first view of Indians or Native Americans, with the common answer being television and/or movies.
As for your "Because Native Americans are oh so unhappy" comment, I don't know what you're talking about. From what I've read, Meyer didn't cast any aspersions on Natives. Not consciously, anyway. All she did was portray them as animals.
For more exchanges with Real Fan, see Noble Savages in Twilight and Twilight's Missed Opportunity. For more on the subject, see Quileute Werewolves in Twilight.
Below: Bella and Jacob--i.e., the white beauty and the Indian beast.