Is 5"4, 50kg and 33inches at the navel fat? Im 18 (girl)?

so im 18 years old (girl) and 5"4 and weigh about 50kg. I hv a huge pot belly. Lol. It measures around 33inches at the belly. Am i fat? Recently i have noticed the pot has become bigger. It has grown by too inches. Also all of a sudden my tshirts have become a little tight and my jeans are tight on the waist. Mum says im growing. But i feel i am putting on weight. What do you all think? I have started to do brisk walking for 30mins and a 5min jog. What can i do. Do you consider me fat or growing? I have no access to a gym. Before i went regularly as i was close to one...i love the gym and working out. But its been a year since havent gone.