black flesh from the vagina

Does she experience the black chunks only when having her period? If so, they are probably blood clots which some women experience at that time of the month. Unless they are really big and cause a lot of pain when she is passing them, this is nothing to be concerned about.
If, however, she is experiencing them at other times, it can be an indication that she is spotting. Sometimes when a woman spots, there is not enough blood to cause it to flow out normally. By the time it is expelled from the vagina, it is old blood and has darkened to black. Sometimes clots can appear more brown in color.
I suggest that she call the doctor's office. Many times a doctor/ PA/ nurse will tell you over the phone whether they feel that it is urgent that you come into the office. And the information costs nothing. If this does not help, she should look into going to a free clinic in the area or your local health department, where you can have medical checkups and procedures done for a fraction of the regular cost.
Good luck.