Simplify the following text for a Grade 8 native English-speaking person.
Original: Among her most influential discoveries are the confirmation of the structure of penicillin that Ernst Boris Chain had previously surmised , and then the structure of vitamin B12 , for which she was awarded the Nobel Prize in Chemistry .
Simplified: She confirmed the structure of penicillin , which Ernst Chain had proposed , and she worked out the structure of vitamin B12 . For her work she was awarded the Nobel Prize in Chemistry .