6 weeks of discoloration in my daughters leg

Hi,  we are currently waiting for referrals and insurance to go to a rheumatologist, which a hematologist suggested.  My daughter is 16 and has this bluish purple discoloration show up on her right thigh 6 weeks ago.  It doesn’t stay for more 6-8hrs, it simply fades away, no color change like in a bruise healing, simply is gone. Now it has spread to her left leg, a stripe down the right thigh and now in the lower leg and left thigh.  Twice now a target/bullseye, sometimes multiple, have shown up on the right thigh also.  Only 3 times has she had any pain and it was for approx 3 mins and felt like getting a shot in the muscle.  No rash, no fever, no illness what so ever.  

Has anyone seen this before?  Any ideas as to what may be causing it? 

It could be target lesions.