[Mawr]

"Not at fault" as far as the law is concerned, is a low bar. If you're one of the last cars in a queue, you should be checking your mirrors for exactly this scenario. Throwing your hands up in the air saying "well the law says I did no wrong!" isn't the way. Unless you like getting into accidents.

Also, having two of the same type of accident twice in such a short time is so improbable, that I'm seriously doubting your friend. I'd say it's way more likely she braked too suddenly or has other bad driving habits that make such accidents more likely than that she got this unlucky.