If so, would she have found it odd that the door was locked? Since they had recently reconciled- would she have had a key to get in the house?
If the lights were out and the door locked, she may have assumed he wasn't there. She might have thought he was at her house.She may not have stopped in.
HR and CR2 may have been dead when she got home. If the bedroom doors were closed and the baby wasn't crying, she may not have looked in the bedrooms. The killer could have been waiting on her to get home. Endless possibilities...