I agree that Sakura changed a little in part 2 from overly fangirling to sasuke and caring about naruto more, but overall her character is mediocore from beginning to end, she could've been a way better character, for the most part her only role was for pairing, Narusaku/sasaku, she had no background, no struggles, she had a cliche tsundere personality, she had like 1-2 fights in the whole enitre manga, overall just no development in anything
She developed personally,allow me to
clarify some
things.
At the begining of the story she was a weak girl who couldn't stand on her own two feet,always watched Naruto,and Sasuke lead the way,and had no special talents.She was an excellent student at the Ninja Academy but didn't put her intellect into use outside of school.
In the Forest Of Death she began to take a stand,and instead of being the one who was always protected,she became the one who protected.She watched over Naruto,and Sasuke while they were unconscouis,and she fought for them,aswell as Lee against the 3 Sound Shinobi,on her own.
Later,she meets Tsunade,and really begins developing her skills.She became the 2nd best Medic Ninja in world,mastering the Hyakugou which even Shizune never accomplished despite being Tsuande's student for years.Sakura attained amazing chakra control,allowing her to do the above and become one of the physically strongest characters in the story.Hashirama himself even said her raw power maybe stronger than Tsuande's.
She played a big part in defeating Sasori,and rescueing Gaara.She wrecked that Bigass Boulder that was blocking the entrance to the Akatsuki's hideout,wrecked two of Sasori's best puppets - the main one,and his personal replica puppet (the one of himself),and jumped in front of his sword and took it head on inorder to save Chiyo's life,and if it wasn't for Sakura's antidote,Chiyo would have died.
She was a big help to the alliance,she was the one who figured out that White Zetsu was perfectly transforming into people and were made from Hashiramas cells - she figured out how they were able to transform and told the top SA guys at the HQ,who then formed a strategy to counter it thus saving many lives.
Later she healed everyone by Summoning Katsuya from that special forest place which is faraway,and used her chakra to power them up to heal everyone thus saving more lives,and allowing them to fight longer.She had enough chakra to allow Obito to use Kamui to open portals to multiple far away dimensions too rescue Sasuke,thus leading the world to being saved.
This same girl who was weak,and always relied on others became strong and able to fight alongside the same people who always protected her,Naruto,Sasuke,and Kakashi.
When Kaguya started to dodge Naruto and Sasuke,Sakura was the one who punched her,thus allowing Sasuke and Naruto to land their hands on her to seal her away,thus saving the world.In terms of power,Sakura,in 3 years developed almost as much as Tsunade did her whole life,and Sakura's not even in her prime.I could go on but i'll stop.
I'll live up to your name for you.