Shrimp/Fish Paste with rice
What you are describing sounds a lot like Belacan which is a very strong, very salty shrimp paste, that can be crunchy, as you describe, if you were to eat it by the spoonful. 

Around where I am (Northern Virginia) you would find ingredients like this in one of the Korean groceries, like H-Mart or Lotte. 

I snooped online looking for your small glass jars. I was able to find some that looked about right on Amazon. Only you can tell what brand your step-mother used to get (if it even exists any more), but it should be very similar to the block form that I am used to.