hi and welcome to '
ask a doctor ' service . I have read your question and here is my advice .
Pain and dark colour indicate that blood flow to the fingers is probably compromised , there could be two reasons mostly, either problem with the blood vessel supplying the finger like
vasculitis,
embolism (
blood clots in vessel ) or atheroscresis ,there are other problems as well.
Other possibility would be Raynaud's disease ,which can be secondary or primary ,( without any cause )
I just wonder that why she removed the spleen as certain blood disorder like sickle cell may also cause plugging of the vessels ( for which
splenectomy is done many times )
Whatever this looks to be a bit serious , and I would suggest she must see a cardiovascular specialist in this regards.
Till that she should keep it warm, avoid smoking ,wearing gloves ,
Hopes this clears your mind, I would be happy to answer if your have any thing else to ask in this regards.