Im not sure if its the same person you are looking for but last friday, July 6, 2012, there was a woman named patricia mckee, 46 years old in an accident. The person who caused the accident died and patricia was taken to the hospital. She was heading towards redstone arsenal which seems very coincidential with your search. Hope that helps, good luck finding your mom.
Copy paste the link below, thats the news about the accident.