The MJ estate is now being managed, and turning a profit, by a couple of entertainment lawyers coining 10% of everything belonging to MJ. I don't blame her for trying to get something back off them.
The family looking for cash in the house sounds normal. They have to see whether there is any, just to stop anyone from stealing it. Given Jackson's lifestyle and eccentricity it is quite likely that there would be substantial sums in cash in the house.