Complex sentence: I always assumed that Mary Jane was his first love, concluding that she was only familiar with Stacy's character from her "The Help" co-star Bryce Dallas Howard's portrayal in "Spider-Man 3".
Split into simpler sentences: I always assumed that Mary Jane was his first love. She further stated that she was only familiar with Stacy's character from her "The Help" co-star Bryce Dallas Howard's portrayal in "Spider-Man 3".