Why did it take 11 months to file a lawsuit?

Typically one does due diligence in ferreting out the facts and circumstances to build up a case before filing. That might mean, for example, hiring a detective to dig up evidence about the event. It's very expensive to sue someone and if you don't have your ducks in order and lose the case, all that expense will have gone for nothing. Bottom line, it takes time to build a case before suing.

For the first few months, she was in mourning. For the next few, she was in contact with an attorney preparing for her case. Her attorney isn't the fastest in the world, so it took a few more months to prepare. Now she's ready to sue.

Ask your friend. We don't know her like you do.

What a bizarre question! How did the daughter die? Insurance companies haggle about pay offs for car accidents for months. If they can't reach a fair settlement, then the person is often advised to bring a lawsuit. These things drag on for years. I'm assuming the lawsuit is for wrongful death? Killing someone is usually a criminal matter rather than a civil lawsuit. She may have been waiting to see what measures the police would take.