Staph infection....

My daughter is 7 yrs old and had what looked like eczema under her arm that just wouldn't clear up...it ends up very red and angry looking.dr prescribed a steroid cream and then a anti fungal cream and antibiotics...also took swabs....results came back that it was staphylococcus aureus.....so he prescribed a different antibiotic and also antibiotic cream and gave me an eradication chart..cleaning sheets etc in hot water...etc....just wondering if anyone has been through this and how long it takes to clear up?we have been treating her for 7 days now and it's no better!grrr....no one else in the family has it and she does get a fair few eczema patches