Near the end of the film if looking closely at the shoulders of their outfits, Violet's rank as an assassin has moved up to 7 instead of 8 while Daisy's rank has moved up to 8 instead of 9.
When Violet and Daisy are shooting Michael with their eyes closed Daisy fires about 8 shots with the slide on her gun locked back indicating that the magazine is already empty.
When the girls shoot their guns with their eyes closed, Violet's gun also empties with the slide back, but in the next shot she fires once more, and then again the gun has the slide in the empty position.
"Angel of the Morning" by Merrilee Rush & The Turnabouts. The complete list of songs can be found here with their corresponding scene descriptions.
Q
Who is Rose and why is she important?
A
Rose is Violet's deceased former partner. It is heavily implied that Violet murdered her, a conversation between her and The Guy suggests that Rose became an informant. This is part of why Violet considers killing Daisy when she finds out Daisy has been using blanks.