Thank you all for your replies. I have taken her to obedience school so she does have training. She has never once aggressively went after the lab, it's only the puppy. For instance, on Friday morning I was sitting on the ground and the puppy came to me so I was petting her and then the basenji came running up and aggressively biting the puppy. I tried to block her from biting but she bit my hand and then she took a chunk out of my forearm. The scary thing was, she wouldn't stop.
Most of the "attacks" (not sure how to word it otherwise) are random. Sometimes the puppy will just be walking away and Marley will go into her aggressive mode and jump on her and start biting the puppy's neck. The puppy will be screaming and it's difficult to stop Marley from biting unless we physically pull her off. This happens about 10 times per day. The ones that I have seen, the puppy has not been provoking Marley.