If Schneider was not being compensated for the baby-sitting, then the only reason for even applying for a visa would be because she intended to stay more than 90 days, and if family reasons was the reason for the application, then she made no fraudulent statement. German citizens don't even need a visa for stays under 90 days.
In every other country, there are NOT always two lines for foreigners and one for citizens. In the UK, there is a line for UK and commonwealth citizens, one for EU citizens and one for third-country citizens. In the EU, it's EU/Schengen (Switzerland and Norway are not EU, but are Schengen) citizens and one for third party, whether resident or not (US has a line for citizens AND green card foreigners, not just citizens).
Some U.S. officials are smart enough to know when there was an intention to violate our laws and when there wasn't. Just like some cops know when someone is threatening them with deadly force and when someone is not. The intelligent ones are not the problem. The stupid ones who like to throw their weight around are. No one dies when an immigration official get snotty with a German citizen (which is why my wife is still alive), but it doesn't help our rep when the story is told over and over again in the home country of the victim of the over-zealous uniforms. This sort of incident filters right up to the top. I know, I talk to these people and have friends in the German Press. To them, THIS is what America is like, not the hundreds of thousands who are passed through every week with no hassle whatsoever.