Realistically she probably had 4 hours between leaving her house, killing him, hiding him, getting back home, cleaning up any major blood/spills before her daughter got home.... unless she went back a second time and moved him. I think he will be found relatively close to home, maybe 20 mile radius. Back roads since she already brought those up/said she was “lost”. Unless she really had premeditation for this, I wouldn’t expect him to be buried or hidden incredibly well. If he is in water, unless heavily weighted, once the temperature starts to rise, he will surface. I’d put my guess on him being in some woods, under snow. Off of a back, desolate, road. Or, if there are any wells/mine shafts in that radius, that’s possible too IMO.
Unless premeditated, she probably panicked and was sloppy. Probably why she’s quickly coming up with excuses and explanations to everything-she’s on edge and nervous. Not confident that she did a good enough job, so she’s thought up these excuses and is over-explaining everything.
All JMO though.