Her poor kids are not even going to remember their mom and how much of her wonderful mother she was to them. I hope her husband and her family help them to know how much a good mum she was.
It's too soon to really know for certain what happened, really. The important thing to remember here, regardless of how she died, is that two young sons will grow up without a mother, and that is incredibly heartbreaking. 25 is just way too young to die.