Okay.
So normally I'd be like "even if you literally stole Naruto's hair and put it on your character, that would not be a reason that you need to change it."
But reading through your post I'm seeing no reasons why you want to keep the character's hair the same? Like, she's had it for 10 years -- okay, is that establishing "no I shouldn't have to change it because I did it first," or is that "I'm really attached to it and can't imagine her in any other hairstyle?"
If it's
Reasons to Change Hair:
- it is distracting to readers who are familiar with this anime
- I am sick of getting these freaking comments
Reasons Not to Change Hair:
- I shouldn't have to because I DIDN'T steal it from an anime
- ????
then, like, trying out some new hairstyles on her to see how they look and possibly tweaking her design isn't caving to accusations of copying; it's just saying, "huh, she looks a little too close to this other character for my comfort, I'm gonna tweak her design a bit." Why not try it out? And it's really nice that it's hair, which is something that people IRL change all the time. You could even just shift the way you draw it to look a little different from the anime in question!
THAT SAID, if you decide you really like her hair as it is and can't imagine her in anything else, having a casual/joke answer for people who compare her to that character might help your blood pressure, at least. For me, having a stock answer ready helps those sorts of comments feel less stressful. Feeling as though you have to convince these people that UGH NO I DON'T EVEN WATCH THIS ANIME I WASN'T COPYING is going to make it ten times more irritating, and is going to make some people just naturally doubt you since you've been put on the defensive.
If you have some kind of stock answer like "lol yeah she gets that a lot" or "haha yeah she could totally be [anime character] for halloween" or even "nah, I didn't get her hair from [anime character] but LOL YOU'RE RIGHT THEY COULD BE HAIR TWINS" then you're not having to prove anything to anyone, and kind of pointing out that it's not that weird for two characters to have the same hair. Anybody who responds to that kind of casual shrug with accusations is just someone who really should calm down and can be ignored, but I'd be willing to bet you won't have quite as many of those!