She knew that Peter was about as useful as a rubber crutch, but with Meg laid up she had no choice. But what Lois didn't know was that Meg checked out of the hospital and really had Lois's back as did Rhonda. With Meg all set up on the tallest building. she look of her Dad. Such as he was, all he ever did was make Megs life miserable. This was her chance to repay him, in spades. So she scanned the roof tops and sure enough there he was, eating, not watching her Moms back like he promised.
The rifle she was using was the new 50 cal. Browning. She smiled as she slid the clip into place and chambered the first and only round she would need. Squeezes the trigger and she watched as her "father's head exploded. She relaxed because she now knew that Mom was safe and could carry out her mission to take out Stewie.