Perhaps, if she WAS taken overnight/early in the AM, she ended up not going to her mom's for dinner/to get the car the night before because of doing said HW. Now, in this theory, I'm not sure what she was doing walking nonchalantly around 730 when the neighbor saw her. Perhaps doing just that? Going for a walk? Maybe taking a break from HW?
So she ends up not getting the car that night. A lot of people are asking what were her plans for a ride then. Maybe she planned to walk and get the car in the morning instead. Tired from HW, knows it's close by. Now I know people have said the weather was awful the next day but it's possible she didn't know it would be raining or pay any attention to the weather reports. So maybe she planned to wake up, get dressed for work, and then walk to her mom's to get the car. The sun would probably already be up by that time unless she was leaving at like 530. But then something happened to her at home before she could leave to get the car.