Continuity mistake: Towards the end of the film, Mattie hands Jenna the dream house he made for her 13th birthday. There is hardly any "wishing dust" on the roof. However, when she goes outside and sits on her front porch, there is plenty of wishing dust all over the roof of the toy house now.
Continuity mistake: In her apartment Jenna walks out into the hallway, looks at herself in the mirror and stumbles backwards over the shelf behind her. There is a short stack of magazines on that shelf, yet when Jenna looks at herself in the mirror the stack of magazines is at least three times as high in the reflection. (00:14:10)
Continuity mistake: When the six girls arrive for the party, in the first shot Tom-Tom tosses her blue jacket, then the second girl lays her red jacket and the third girl starts to put her pink jacket into Jenna's arms. Yet, at the start of the next shot facing Jenna, she holds only the blue jacket, since the red jacket is gone, the pink jacket is placed in Jenna's arms on top of the blue jacket and then the red jacket is thrown into her arms from off camera, before the rest of the girls dump their jackets into her arms. Then in Jenna's close-up, the jackets are positioned very differently in her arms. (00:08:15)
Continuity mistake: When Jenna and her boyfriend sit on the sofa, there is a basketball on the sofa which disappears between shots. (00:45:15)
Continuity mistake: When Jenna is 13, she enters the closet at her party and between shots from when she tells Tom-tom where the projects are, to the next shot of her, the blindfold tied around her seems to turns upside down. If you look at the pattern (stripes) it flips over. (00:10:05)
Continuity mistake: When Jenna enters her office she throws her silver bag on a chair, and as she walks over to the photos you can see the bag is laying on it's side. When the woman knocks on the door you can see the silver bag again, but now it's standing upright, as you can tell by the straps/handles. (00:22:00 - 00:22:40)
Continuity mistake: When Jenna and her best friend are outside the office in the beginning of the film, the amount of hair tucked behind her friend's ear varies from shot to shot.
Continuity mistake: When Alex walks into the hallway wearing a towel, the towel is wrapped around him differently in the first shot when he asks Jenna for conditioner and then when he whips the towel off. (00:16:20)
Continuity mistake: When Jenna first sees herself in the mirror as 30 she falls over the side and then looks over it into the mirror. In a shot facing her, only her left arm is on the side. Then in the next behind shot now both her arms are on the side. When it cuts back to the previous angle only her left arm is on the side again. (00:13:50)
Continuity mistake: When Jenna first walks around after turning 30, the camera pans around the apartment and we get a good view of the small glass table in the lounge, and there is a remote control next to a magazine. When Jenna goes and sits on the yellow chair though, the remote is now on the magazine. Later when Jenna is throwing her letters, the remote has moved to its original place. (00:13:30 - 00:14:45)
Continuity mistake: After Lucy's meeting about her new "Poise" design, she storms out frustrated, and whacks a box to the floor causing items such as a few bags to scatter on the floor. Between shots the bags move majorly. (01:10:45)
Continuity mistake: When Jenna, as a 30 year old, goes to her office for the first time (after her first meeting), she opens the door and has no handbag in her hands, in the next shot it shows her closing the door behind her and she throws her handbag onto the couch. (00:22:40)
Continuity mistake: Jenna's white drink at the party repeatedly changes - the amount of drink inside rises and lowers between shots. (00:34:20 - 00:36:00)
Continuity mistake: Outside on the sidewalk, Lucy is giving Jenna a lecture on going into the office for the first time. The same woman in a purple dress walks by 3 times (behind Jenna.)
Continuity mistake: When Jenna first realizes that she is thirty and she walks down the hallway, there is a pile of magazines on the counter with the mirror. Then in the next shot, the pile of magazines isn't there.
Continuity mistake: When Jenna is talking to Matt and his fiancee on the street, they leave, and then Lucy turns and starts to walk off, and she has a cigarette in her right hand which she puts it into her left hand. Then when the shot changes the cigarette is back in her right hand. (00:44:20)
Continuity mistake: When Matt and Jenna meet at the park before the photo shoot, Jenna hands Matt the envelope. In the shot facing Jenna she holds up the envelope with her left hand, but in the next shot the envelope is in her right hand as Matt takes it from her. (01:02:35)
Continuity mistake: In the scene where Jenna meets Matt's fiancee Wendy and then introduces them to her boyfriend Alex. As Matt and Wendy are leaving, Alex says "Nice to see you folks" and a second later as Matt and Wendy pass in front of him, he says "Nice to see you folks" again.
Continuity mistake: When Jenna goes to her boyfriends house, they sit on the sofa and then the boyfriend places two glasses on the table. He then puts his right arm around Jenna, and his left arm lays on his leg. Then when it cuts his left arm is laying on a cushion. (00:45:15)
Continuity mistake: In the basement, when Tom-Tom tells Matt that Jenna is in the closet waiting for him, the TV is angled facing towards the stairs. However, when Jenna looks out from the closet to see everyone gone, the TV is facing the closet. (00:11:20)
Answer: Jenna asked the girl, "Can you tell I'm wearing underwear? Because I totally am". This is because when she was 13 just a day before, she was wearing big underwear. Now she's wearing a thong, which wouldn't be visible when wearing a dress.