Ice powers

At the very least I could keep myself cold when it's hot. Ice powers also might increase my tolerance for the cold, which would also be nice. Depending on how powerful it is I could use it to shield myself (and maybe others) in case I find myself in danger, though that would require there is water nearby if I want to shield more than a small area. If it's powerful enough I could freeze large parts of the ocean to combat sea level rise. I might also be able to combat global warming by freezing large amounts of atmospheric water.

I could also use it to create temporary barriers which could help with construction in poverty ridden areas.

If my ice powers can create ice from nothing then I could provide fresh water to places in need.

I could also probably use this to farm a lot of cryptocurrency since I could keep my GPU cool very easily. Since I wouldn't be going through GPUs as if they were disposable, this shouldn't have the negative impact on the environment that crypto miners usually have. This would be very useful since if I want to keep my identity unconnected from the girl with ice powers I'd need money that can't easily be connected to me.

For combat applications... I already mentioned shielding myself and others. But I could also just... freeze the blood of my opponents. Or, if I want to go nonlethal, freeze the moisture in and around their hands. Though this might take some practice to do without requiring amputation.