The name means 'pure'. There's a lot of misinformation here. It's a gorgeous name. Y'all need to get over what happened 15 years ago. Plus there were 2 hurricanes named Katrina and everybody's done already forgot the first one.
I went to Ireland and went to the Island Inis Moore which is the last place where Gaelic is still the main language. I stayed with a native there and when my friends and I asked how to say our names, I found out "Katrina" is said they exact same way - so it's ORIGINAL origin is actually Gaelic. Very cool!