I understood that LS rented the Rio on the pretense that she was going to drive around looking for GS -- stating that it would be best for her to be driving a vehicle that he did not recognize -- fearful of getting in trouble. (And she added the excuse about not wanting to add mileage to the leased VW for an extra touch of LS drama).
Although we did not know for certain, LS certainly knew GS was dead and where she stashed his lifeless body long before she collected AS from the airport.
Guilty, I can't imagine LS wanting to be anywhere near AS or LH (that were truly worried, anxious, distraught) knowing they'd confront her with crucial questions that she could not answer or catch her in more lies. No way was LS going to give them that chance! For example, investigators reported that LS never went to any of the neighbors to inquire about GS or whether or not he'd been seen. LS did not call any of his friends. LS did nothing that a prudent parent of a missing child would do.
IMO, the disconnect was that LS had just killed their child yet she was also put out that her archenemy was crying and pacing in her own home together with her husband!
On the other hand, if GS had disappeared through no fault of LS, I don't doubt that we would have found LS side by side GS parents-- trying to get on TV, set up a command post, organize searches, etc-- all for the attention, praise, and adulation that LS desperately craves.
Instead, LS immediately went to CYA mode, defending herself before it was necessary.
And worst of all, she clearly took gaslighting LH up a few notches in reaction to her own guilt and evil act.
MOO