yea, replace the battery, check the battery terminals for corrosion, check the starter cable. then get an induction/injector cleaning job at a local shop, not all shops have induction cleaning, but it will be Well worth it on any car that is over 5 years old. it will clean all the carbon buildup in the EGR system, the intake manifold, intake and exhaust ports, and valves, etc.

if your aunt is elderly and didnt drive much, injector cleaning is a Must, gasoline goes bad after a couple of months, and older folks can use 1 tank of gas for like a whole year. one run of bad gas and your injectors will be practically useless.

after that its all electrical problems, need to take it to a mechanic to get the problems identified