Continuity mistake: When Tony lies dead, his head is facing right or left between shots, no continuity whatsoever despite Maria not touching him.
Continuity mistake: When one of the Jets jumps on the pickup to unload all the veggies and watermelons, the car on the left changes between shots. Also, when he is about to unload the veggies, the pick-up is approaching a blue squared van on the left. The shot changes, and the van is further away.
Visible crew/equipment: In the officer Krupke song, set lights are visible on the stairs to the audience left and right.
Continuity mistake: When Riff tosses cans at Tony, Tony's right arm is raised. A shot later it's lowered.
Continuity mistake: When Tony is below Maria's fire escape, there's a shot of her back with her fingers grabbing the platform. Shot changes to Tony's POV where she moves her hand and changes her grip. Then shot goes back to the previous angle of her still with the same grip.
Deliberate mistake: When the gangs meet in the toilets to set a date for the brawl, the mirror on the left is the only one opaque, most surely to avoid reflections of the filming crew.
Factual error: Suspended traffic lights didn't exist in fifties NYC.
Factual error: At the beginning of Quintet, a modern Manhattan skyline is visible in the distance not a late 1950s skyline. Also, the view is consistent with the Paterson, NJ filming location, not the Upper West Side.
Audio problem: When the Mambo song starts playing, the bongos player is way out of sync in every single shot.
Answer: No, she doesn't, but Tony is shot and killed.