What Causes Breasts Spots With Redness, Pus, Scabbing Leaving A Residual Hole?

my niece has a spot on her left breast that looks kinda like a boil. she wears a double d bra and the redness around the spot covers almost half of the left breast. she also has a spot near the other one that she got pus out of and it looks better. but the big one leaked pus now and she took hot shower and the scab came off and now there is a deep hole in the center of the boil. she also has body pain in all her joints and feels a little under the weather.
What should we do?