^^This.
They/she would also have not left the body in their home, knowing that it would incriminate them. If Patsy knew Jonbenet was in the basement and would be found, wouldn't she have gone down there to "discover" it herself?
They may not have had a choice. Keep in mind that leaving the ransom note while the body is in the house makes no sense in both the RDI and IDI theories. The difference is that the intruder can bring the body with him and dump it without ever returning to the Ramsey House. The Ramseys don't have that luxury.
You also have to consider that John may not have told Patsy where JonBenet's body was. I think the issue of disposing of Patsy's body may have a huge issue with them. Patsy wanted her to have a "proper burial", while John wanted to bury her while he supposedly went to the ransom drop. This was the big mistake they made. They became sentimental over their daughters body.