Found this on a Medical website:
Symptoms
Children are not usually affected too badly, and often the first manifestation is the rash. This is a fine, pink rash spreading from the forehead and face downwards. The rash may last for 1 to 5 days. There are often some of the glands (lymph nodes) enlarged, especially behind the ears and on the back of the head. Adults often feel more unwell before the rash appears, and may have pains in the joints rather like arthritis.
HTH. It has an incubation period of 12-14 days, so your dd may have been in contact with it 2 weeks ago... if that helps you place where she got in from. The important thing is to keep her away from pregnant women.