Hallo
Last weekend I had yellowning of my eyes, I am on Doxil, no Carboplatin. I went to the doctor for liver enzymes check, and everything including billirubin was fine, like you describe it for your mother. My doctor asked me wether I was recently eating a lot of carrots. I was surprised, I didnt know, that that might color the white of the eyes. But indeed, I was drinking a lot of betacarotin containing commercial multifruit juice in addition to the juice from a pound of abricots and mango. I even have the impression that avoiding this for 2 days now improved the whiteness of my eyes. That may be a coincedence, but I thought, I will tell you that possible explanation by my doctor. Hope that your mothers eyes get well very rapidly and that the chemo otherwise is doing the wanted effect.
You should probably contact your chemo clinic right away for advice as eye whites yellowing usually indicates liver function problems.