Im 21f 5'6 height with broad body but it seems my face didn't grow after 15years. it is very thin and small doesnt match my body. pls give solution?

No "solution" exists: for a perceived "mismatch" between the size of the head and the rest of the body. Most of the growth of the head and skeleton of a girl is complete by age 15. If you're overweight, wt. loss may make you feel better. Even the most beautiful young women are unhappy w/ some aspect of their looks. Fortunately, as they mature, most women get more comfortable with what nature gave them.