From what I understand up to this point that is correct.

Try to picture it like this, they arrive early while she's still sleep and wake her. Tell her the bs story I mentioned in my other post, 1 cop consoles her, the other "looks around the house". The 2nd cop finds the needed guns, preps them, and then calls down to his other cop buddy to come upstairs and take a look at this (the mother follows). She comes into the room to the 2nd cop with 1 of the "patsy" guns in hand (I don't remember hearing exactly which of the 4 guns was used on the mother). They tell her to position herself a specific way on the bed (again what option do you have when a person has a gun pointed at you). She does it, and they shoot her when she is in a convincing enough position. They then take her car with the 4 stolen weapons and head to go pickup Adam the patsy. Official it would appears that she was killed by Adam in bed (still in pajama's, no signs of forced entry, patsy guns missing, bullet type in mom & at school match)... no loose ends, nice and clean.