My thawed breast milk smells fishy (not soapy or like bad cheese). Is it okay to give my daughter?

If you want to minimise the fishy smell, try scalding freshly expressed breastmilk before storage. Scalding milk inactivates the lipase and stops the fat digestion process. Nutrient levels may be lowered but it is not a huge issue unless all the milk is at a rolling boil. Scalding the milk involves heating the milk to about 82 degrees celcius, when you see bubbles forming at the edges of the pot. http://kellymom.com/bf/pumpingmoms/milkstorage/lipase-expressedmilk/