It seems like there might be a typographical error with the name "Letita" in your question; I will assume you are referring to "Letitia" or the original name.
Regarding the scenario you presented, if Letitia is a 20-year-old woman who has stopped growing two years ago, this is generally considered typical for females. Most women experience their growth spurts during puberty, which typically occurs between the ages of about 10 to 14 years, and they usually reach their adult height by around 16 to 18 years old.
Since Letitia is now 20 and has completed her growth, it is likely that she has simply reached her genetic potential height. This is a normal aspect of human development and is not indicative of any health issue unless accompanied by other symptoms.
Furthermore, being in college studying to become a teacher indicates that she is on a positive path in her education and career aspirations. Therefore, she is likely just at a stage in life where she has completed her physical growth and is focused on her studies and future profession.