What are ways or tips for 14year old girl to grow taller before her period? what should she eat to be taller?

Just be healthy: At the age of 14 and in the absence of illness, there is nothing to do except to stay healthy and eat healthy. Height is mostly genetically determined.

Normal diet: Absent problems with starvation or vitamin deficiency there is nothing you can do to influence genetically predetermined height. Although small stature has been associated with dietary insufficiencies, particularly in childhood, at age 14 she will grow taller or not, and diet will not change that.

Balanced diet : Adequate calcium and vitamin d. Be sure she is not anemic could need an endocrine assessment.