My 29 month old daughter has been complaining of back pain, leg and arm pain she has an undiagnosed bleeding/blood disorder could the pain be related?

Depends on which: bleeding disorder she has. I assume a pediatric hematologist is evaluating her. Whether related to her blood disorder or not, she's in pain & needs to see her pediatrician. Kids that age don't complain about aches & pains for no reason. Take her temperature when she complains. 100.4 degrees F or above is a fever. Note any joint swelling, tenderness, heat, limp,decreased appetite or activity level.