I'm not who you replied to but say Nino's development has no nuance is a huge mistake. The first couple chapters had her hating him. Then as time passed on she grew to feel fairly neutral towards him. The neutral feelings started when Fuutarou helped Nino out by trying to get all the sisters together for the fireworks. She let him into her room so he could do her ear piercing. She still listened to his lessons while they were studying for their first exams. She could have purposefully failed and snitched on him but she didn't. Instead, she saved his job so that he could get another attempt at helping them.
Then there is the camping arc where she met Kintarou. She was willing to give Fuutarou the bracelet she got from Kintarou, the man she fell in love with, to help Fuutarou get better. That shows how much she mellowed out towards him especially to the point where she is hoping he gets better soon.
Then we get to 7 goodbyes and she listened to his story about Rena and was studying on her own using the worksheets Fuutarou gave her. They were getting along just fine when there was no mention of the tutor role and were able to hold a serious and normal conversation. She hated the job that Fuutarou was given and thought it would ruin the comfortable family dynamic she loved so much because Nino herself was afraid of change.
At the end of 7 goodbyes, Fuutarou saves Nino's life and Nino herself was confused to who her feelings were for: were they for Fuutarou or the lingering feelings of Kintarou? Between chapters 50 and 60, like 3 full months passed and during those 3 months Nino was trying to figure out what her feelings for Fuutarou were. She figures out that she does like him and thinks since that he has finally done his job that he will never be a part of their lives again, so it wouldn't be worth saying anything. This all changes when Fuutarou arrives as her prince charming on a bike and takes Nino with him back to the bakery.