parallel between ellaria sand and catelyn stark coincidence or foreshadowing

[silverwolf22]

Catelyn waited until they had quieted. “My lords,” she said then, “Lord Eddard was your liege, but I shared his bed and bore his children. Do you think I love him any less than you?” Her voice almost broke with her grief, but Catelyn took a long breath and steadied herself. “Robb, if that sword could bring him back, I should never let you sheathe it until Ned stood at my side once more… but he is gone, and hundred Whispering Woods will not change that. Ned is gone, and Daryn Hornwood, and Lord Karstark’s valiant sons, and many other good men besides, and none of them will return to us. Must we have more deaths still?”"

“Oberyn wanted vengeance for Elia. Now the three of you want vengeance for him. I have four daughters, I remind you. Your sisters. My Elia is fourteen, almost a woman. Obella is twelve, on the brink of maiden-hood. They worship you, as Dorea and Loreza worship them. If you should die, must El and Obella seek vengeance for you, then Dorea and Loree for them? Is that how it goes, round and round forever? I ask again, where does it end?” Ellaria Sand laid her hand on the Mountain’s head. “I saw your father die. Here is his killer. Can I take a skull to bed with me, to give me comfort in the night? Will it make me laugh, write me songs, care for me when I am old and sick?”

 

remember what happened to  the starks and the north what will happen to the sand snakes and dorne

[Euron III Greyjoy]

I wouldn't really say its foreshadowing anything. I imagine most mothers wouldn't want their children to go off to war for the sake of revenge. 

[Quoth the raven,]

Jamie, Cersei, and Catelyn ignited the WOT5Ks over Bran.  Ellaria is willing to forget revenge to save the lives.  They're not the same at all.  Ellaria cares for her people.  Catelyn thinks she cares for the people but she is all about family.  I like Ellaria's attitude better.  

[Seams]

I think there is a parallel. Nice catch.

Catelyn's anti-war speech at the end of AGoT is characterized as a whisper that isn't heard; the woods whispered its message against slaughter and it was not heard, either.

The scene with Ellaria includes the skull of Ser Gregor which - aside from its Hamlet / Yorick / gravedigger echoes - also parallels Catelyn's upcoming scene with Ned's bones laid out by the Silent Sisters.