I have that exact same peace lily.
The important lesson i learned about these is to only water when the plant starts to droop.
when i first got it i lost most of the leaves due to overwatering and fertilizing.

Now i only water when the leaves start to droop and a few hours after i water it it perks back up!

Good luck with it, this is a rare cultivar called "silver streak"

Here is a pic on what mine currently looks like.
The leaves that are damaged have not gotten worse since i corrected the watering.

Thanks tlbean.
Fred

tlbean, this is the one that died. I put it outside under a tree as a last ditch effort, but the increased humidity sent it into free fall. I still have the large one though.
Fred

I don't think it's a peace lily. I never saw one with a white line down the middle. I think it's a Diffenbachia.

it is a Spathiphyllum "Silver Streak"

tlbean, I divided my Silver Streak this spring. Now the smaller piece is in trouble. I repoted it yesterday but it did not perk up over night, totally in transplant shock.