Are you using clean water? It looks like a water / soil issue.For the heighth of her she doesnt look like she has had a good life. Get a soil PH meter and check it out. Looks like bark in your soil, this can have a very acidic reaction to the poor girl. Good luck need more pics of the entire plant. Does your soil drain well? Doesnt look like nute burn. Normally with that the end of the leaves will get rounded and malformed rather quickly.