they seem to have a very complicated relationship. You might want to have a look at the old Princess Haya thread for a more recent disscussion on the subject:
http://www.theroyalforums.com/forums/showthread.php?t=6401&page=8&pp=20
(Pages 8 and 9)
Princess Haya and Prince Ali apparently harbour some resentment towards Noor since King Hussein married her soon (I think a year) after the death of Queen Alia. I find it odd that Haya and perhaps Ali have this attitude towards Noor and not towards their father who was, after all, the one who asked Noor to marry him.
When King Hussein was alive, Haya and Ali publicly spoke warmly of Queen Noor. But since his death their relationship has seemed to cooled off. Some people have said that Noor wasnt a warm step-mother. But then she doesnt come across as a particularly maternal person (like Queen Rania for example). Ofcourse that doesnt mean she wasnt capable of being loving.
I think its safe to say that whatever relationship and level of interaction Haya and Noor had with each other has diminished significantly since King Hussein's death. Noor wasn't at Haya's wedding, nor the wedding of her brother Prince Ali.