Accidentally put 89 octane instead of 87?

I filled up my grandmas 2010 Honda Fit yesterday and I accidentally hit 89 octane instead of the regular 87 she puts in. Will this harm the engine? She does 100% city driving and has roughly 25,000kms on it if that helps.

Added (1). I should've said otherwise. It wasn't really accidental. The machine said "the grade selected is unavailable" so I pushed 89. Just clarifying.

Don't worry about it.

Using a lower octane rating than the engine is designed for can cause issues with engine pre-detonation ( otherwise known as engine knock ) but using a higher octane rating won't hurt anything except your wallet.

These people are full of advertising and tall tales.
Octane rating of fuel is supposed to match the recommended octane in the owner guide.
Cars that use higher octane are made a little different where the shape of the cylinder head chamber is.
( If your car uses 87 you can use them all.)
If your car requires high test, you must use high test to avoid pinging preignition and detonation.
Octane is an engineers expression of a materials ability to turn to vapor. High test, or high octane simply means it won't vaporize as easily.
Cars with a special chamber use high test because the low octane will ignite too soon in the same environment.
Sure, they will argue with you, but they arent engine builders, driveability technicians or even as educated as a gas station attendant.
Stories about additives being measurably different, the fuel producing more power, or making your car run hotter or cooler are
made up by people who have the info jumbled up in their heads.
They listened to part of the info then imagined the rest.
Their attitude and spreading misnomers is part of the reason you don't get true and complete answers about things you can use to accidentally hurt yourself with.
Most of those things become unavailable to you, and replaced by something you have to spend more on to try and achieve the same effect.
Give them a child's toy and they hit themselves over the head with it. Maybe thats not such a bad thing after all.

The rec is the minimum. If you went to a higher octane, you just might see better fuel economy.

You can put ANY grade in. The cost per gallon is on the pump so you get less for $40. And not get say super fuel economy because of it. Just a bit better.
. You could go nitros-alcohol but that is costly stuff. A little bit more peppier, but nothing else. It is still a 1500cc 4 banger.

No adverse problems will happen. You simply paid a bit more for your tank of gas than you had to. That's it!

No, it won't hurt at all. It probably just cost you a little more.

It won't damage it's even better for the engine since it has more addictives it clean out more rust but the price it's much higer. Don't put premium gas since that is for turbo cars

Absolutely not, if anything it will benefit her engine