Question about my little girl...she turns blue

Dear Doctor,
I thank you in advance for your time. As I type now I am waiting on a return call from my pediatrcian because I want my 2 year old to see a pediactric cardiologist. Just to give you a brief history my daughter was born at 26 weeks gestational age and weighed approximately 745 grams at birth. She had multiple problems but appears to be thriving now. I have noticed on many,many occasions that her hands to her elbows and her feet turn blue black. Never around her mouth and she never appears to be in any type of respiratory distress while this is going on. After a short period of time she pinks up again. This occurs predominately in cold weather but she will do it when it is actually warm and also after waking from a nap I have noticed it. I have brought it to the attention of her pediatrician before and they say it is normal. They listen to her heart and say she is fine. No other studies have ever been done. I say it is not normal for a 2 year old or anyone to have cyanotic episodes without further investigation. I am going to push for the referral to get her seen by a specialist. Am I doing the right thing or am I just a paranoid mom?? Please tell me what you think. I really appreciate it. Thank you!

[CCF CARDIO MD JMF]

Dear Leigh,

I would pursue a diagnosis.  You are doing the right thing.  Please let me know if I can be of further assistance.