Hi nelly111s,
I’m glad to hear she was able to get signed in. Just to verify, does it only crash Group FaceTime? Can she accept and make FaceTime calls to just one individual? What about Group FaceTime audio calls? If so, this is expected behavior. ‘To use Group FaceTime video calls, you need iOS 12.1.4 or later, or iPadOS on one of these devices: iPhone 6s or later, iPad Pro or later, iPad Air 2 or later, iPad mini 4 or later, iPad (5th generation) or later, or iPod touch (7th generation). Earlier models of iPhone, iPad, and iPod touch that support iOS 12.1.4 can join Group FaceTime calls as audio participants.’ This article has more info:
Use Group FaceTime on your iPhone, iPad, and iPod touch
To verify if she is indeed using an iPad mini 2 and not an iPad mini 1, have her enter the serial number in the following link:
Check Your Service and Support Coverage
This can help you confirm what device she has and what FaceTime options are available to her. If it’s a first gen iPad mini one, she is on the latest iOS and will need to use a newer device to do a video Group FaceTime.
Best wishes.