What is the main problem in "A Worn Path" by Eudora Welty?

The main problem in "A Worn Path" by Eudora Welty is the fact
that Phoenix is an old, poor black woman who has sole care of her terminally ill grandson who
accidentally swallowed lye.  In order to care for him, she must travel a long and arduous
path--albeit worn--to the free clinic at which she can obtain some medicine to ease the boy's
symptoms and pain.  Along the way, Phoenix is knocked down by her poor eyesight which causes her
to imagine ghosts, her aged knees which give way and cause her to fall, and the buffetting by the
subtle racism of the white hunter.  Nevertheless, like her name, Phoenix rises and continues on
her path of love until she arrives at the clinic.