Re: possible immue problem.
It's not usually related to an immune problem. What it is is a drug resistant strain of bacteria normally found on the body, and is becoming much more common. Antibiotics that are normally used to kill staph infections won't work on this strain, and stronger ones are needed. That is why you should ALWAYS take the antibiotics as prescribed, and take them for as long as prescribed, unless the doctor tells you otherwise. Not finishing them leaves bacteria in the body, and this encourages the bacteria to recognize the antibiotic in the future, and mutate into a different form the antibiotic can't work on.
Your daughter should be fine, but your family should be tested as well.