PLease research the following topics:
Do you have well water? High nitrite/nitrates in water and also any coliform bacteria can cause Methenoglobiemia (decreased oxygen carrying capacity of hemoglobin).
Have your doctor test her blood for methoglobin levels.
Beleive it or not even municipal water supplies can be contaminated. The last time I checked Livermore's water we had freon, of all things, in our water supply... and also we were above recommended safety limits on nitrites / nitrates.
Deep vein thrombosis (Blood clots), heart murmers, epiglotitis, can also contribute to cyanosis. I also believe certain bacterias in the blood / body can contribute to poor circulation problems. Certainly bacterias have been known to affect heart and veins.
ps..try Organic live Manuka honey internally 4 x or more a day- which oxegentates and kills bacterias. (you can always find it online..I think vitacost.com has it at a good price )