I am a 14 year old girl sometimes I get puffy in the place where pee, I don't know what means should I convince my mom to take me to a doctor?

Are you in any pain or discomfort? If not, you are almost certainly fine. Most parts of the human body are prone to a certain amount of swelling at times.

If you are in pain, or getting sore when you pee, then go to the doctor.