No, she probably doesn't. Dovepaw is the one that likes Tigerheart. Ivypaw just said those things in Night Whispers for her sister to feel bad.
Ivypaw and Tigerheart had a complicated relationship. At times, Ivypaw showed affection towards Tigerheart, but ultimately their relationship faced obstacles due to their different loyalties to their clans.
Yes and no.
The book has not come out yet. No, it has come out, and yes, Dovepaw does fall in love with Tigerheart, but in the end, Dovepaw gets kinda jealous because she thinks that from the way Tigerheart nodded to Ivypaw because they saw each other in the Dark Forest, Dovepaw thinks that Tigerheart might like Ivypaw. I'm sure that Dovepaw still loves Tigerheart, but I wonder what would happen?
Ivypaw is not interested in anybody yet. She used to be in a one-sided love with Tigerheart (from ShadowClan) but he loved Dovepaw. However, Dovepaw believes that Tigerheart does not love her so in a way, they broke up. Ivypaw will probably be interested in someone after she gets her warrior name which is in Signs of the Moon.
Tigerheart did harbor feelings for Ivypaw during their time in the Dark Forest. However, after realizing that their relationship was built on deceit and manipulation, he ultimately chose to be loyal to his Clan.
It is very unlikely that they will become mates. Tigerheart and Dovewing both love each other but Dovewing is mad at him for using her to get herbs. Bumblestripe and Tigerheart both show affection for Dovewing.
In The Fourth Apprentice, when they are going to find out what is drying up the lake. When Dovepaw gets nervous, Tigerheart brushes his pelt against hers and says, "Don't worry, I'll protect you!"
She isn't told, but she over hears Tigerheart and Tigerstar talking. It reviles that Tigerstar had been lying to her. He was not helping thunderclan.
There will probably be a battle between StarClan and the Place of No Stars. Lionblaze may get a mate. Tigerheart and Dovepaw will start meeting in secret. Dovepaw and Ivypaw will get their warrior names.
What Happens in Night whispers is: ~Tigerheart confesses he likes Dovepaw, Dovepaw confesses she likes Tigerheart. ~Dovepaw and Jayfeather find out Ivypaw is training with Dark Forest cats. ~Jayfeather finds out that cats from all clans are training with the Dark forest cast including: Ivypaw, Tigerheart, and Breezepelt. ~Jayfeather has a dream that the Dark Forest Cats attack Thunderclan and Ivypaw is the only one who isn't hurt. ~Lionblaze loves Cinderheart but is afraid to tell her ~Cinderheart tells Lionblaze she loves him, too ~Cinderheart and Lionblaze break up ~Flametail dies and Jayfeather desperately tries to save him. ~Dovepaw and Ivypaw have a fight. ~Lionblaze is very frustrated by the battle. ~Littlecloud is sick ~Flametail hates Lionblaze for killing Russetpelt. ~Rowanclaw is the new deputy. ~Dovepaw gets angry at Jayfeather for calling her sister an enemy. ~Brambleclaw has still not forgiven Squirrelflight.
Ivypaw does not have romantic feelings for Bumblestripe. They have more of a friendly relationship as fellow members of ThunderClan.
Ivypaw hates Dovepaw because Firestar listens to her and Dovepaw is singled out like a super warrior.
Ivypaw harbors feelings for Toadstep, but it remains unrequited as Toadstep is interested in another cat. This unrequited love contributes to Ivypaw's internal struggles and growth throughout the story.