Immigration typically ask how long, especially if she is a single women. Since she has a tourist visa approved, she just needs to prepare and show her itinerary.
Normally the migration just stamp the standard 6 months even though you are only going for 1-2 weeks.
Answering you are staying 5-6 automatically raises red flags, especially if it’s her first time in US and single.
Majority of tourists don’t stay that long. They will ask for all the proof of accommodation, contacts, why you need to go for that long etc.
How her company would allow her leave that long, how much money she has etc.
It’s better to say 1 month. Have detail list of friends name, address, phone. What her plans are weekly.
You can also book hotels on agoda, which many allow free cancellation from a week to 2-3 days prior to check in. This will help establish you have a real booking, and can show the officer on agoda app. Booking for car rental / domestic plane flights helps too.