Did my fiancée commit insurance fraud?

Earlier this year, my fiancée was contacting by a roofing company who was doing a few jobs in the neighborhood. After an inspection, a rep from her homeowner’s insurance was sent out and she ended up getting a hefty check to put a new roof on.

However, she’s decided to sell the home, cashed the check into her account, and not put a roof on. Obviously I feel like she may be at risk here. Is this fraud? She’s hellbent on doing this. What happens if her insurance company or her mortgage lender found out?