So my friend is coming home from florida in the next few weeks and I was wondering if she brought some ocean water in like water bottle if that would be allowed on the plane

As long as it is packed in a TSA-approved container, there should be no issue transporting sea water in luggage.

Probably in a travel size shampoo bottle it would work

I would keep it under 3.5 ounces

Not sure how that would be labeled so probably not allowed. I know no drinks are allowed past security. Although if it was packed tightly in luggage....🤔