So typically, the at-fault party would be responsible to "make whole her losses" in a crash, including replacing seats that needed to be replaced. However, since the other party is uninsured, it's a bit tricky. If she had an uninsured rider to cover this situation, tell her to use that language, that she needs her losses made whole, and provide the statement from the manual that they must be replaced as proof if needed. If she doesn't, she may be out of luck as what an insurance company covers in that situation is limited and Wisconsin is not a state that specifies that car seats must be replaced by insurance. She can still try providing the manual and asking to be made whole, and can contact Graco for additional documentation that they must be replaced, but there's a chance they won't budge.