In NY we talked to 4 AA agents, two of which seemed confused, and the other two were confident that in London she'd have to get her bags at luggage pick up, take them through the immigration check point, and then check them in again for her flight to Moscow.
In London she waited for her bags, and waited some more. Then it turned out that the bags were moved to the next flight automatically and that she didn't need to get them. Because of this she missed her flight and had to spend the night in London.
Today her flight from Moscow to London was delayed by more than 3 hours, making her miss her connection in London. She hasn't arrived in London yet, so I don't know what she'll do once she gets there. And I feel so helpless... I called BMI to ask them about their flight from Moscow. The idiots didn't even know it was delayed.