So I was rereading the last hope (because I can) and I read Ivypool's pov and in it and I found something interesting. When she meets up w/ Hawkfrost (this is when she is acting like she's part of DF) he tells her that he wants her by his side when the fight in WC starts. (not in the exact words but still.)
Then when Ivypool turns against DF Hawkfrost tells Snowtuft and Thistleclaw to kill her. Most likely because he didn't want to kill her himself and he says he'll kill TIGERHEART!! His own kin!
Also because I know some of you will probably be saying that when they fought again he said he'd kill her, that maybe because Tigerstar was watching and we all know that he could never revel his feelings because of Tiggerstar. I know this for a fact because after Hawkfrost dies (Rip Hawkfrost T-T) Tigerstar comes out and and tells Bambiclaw "Well done, Brambleclaw." Which means he was most likely watching the fight.
The end.