My mom wants to go shopping with me and my friends >:^( ?

okay soo me and my other 2 friends wanna go shopping for dresses for the vday dance...were all 13..But my mom wants to come too and i know how she is when were in the mall, she agitates me, like she may get a me a dress a 7 year old would wear and i keep telling her im to old for some stupid kiddie dress...iknow she wants to see how my dress will look on me so i wont look like a hooker but i just wanna go shoppin with my friends and not have her cramp my style...so how can she still go with me to the mall but not cramp my style as in choosing something for me that i absolutely HATE...and i was thinkin bout my other friends moms can come and they mingle and stuff while we do stuff our way...please help me...cuz she treats me like a 7 year old..thank you cuz im like stressing my self out really bad...