What's wrong with her?

The purpling is usually due to cool temps at night. She is also hungry for Potassium (K) and a bit of extra nitrogen wouldn't hurt either. Add a P/K booster to your ferts and maybe give two feeds with half grow and half bloom nutrients to top up her nitrogen availability. After that go back to straight bloom nutrients and continue with the P/K booster until about 3 weeks away from harvest, as she won't get any extra benefit from the extra P/K (phosphorous/potassium) once she gets close to maturity. Going by your picture, you still have another 4 weeks or so of flowering to go, maybe even 6. Start a flush (in reality, just stop giving fertilizers and give just plain water, it is not an exercise in drowning your plant!) once she has 95-98% brown pistils and harvest when she has 98-99.9% brown pistils, usually about 2 weeks later, and this will put you in the "10-30% amber trichomes" zone without having to look too hard at your buds. Once a plant has 100% brown pistils, THC breaks down rapidly into CBD and CBN, which are 2 non-psychoactive cannabinoids that don't get you high, but they do make you sleepy! Hope this helps, Organoman.

Ph and or a lockout. And looks like it’s a touch cold in the room—maybe at night? You are getting purple leaf tips. Flush and get back on the bloom nutes

Nitrogen is mobile and starts at the bottom. Looks like potassium or micro nutrients deficiency. Make sure your pH is correct for whatever your growing in. My guess is it's not balanced causing a lockout.

Hey men, que bellos van esos cogollos, pero lo que veo son las puntas de las hojas se están empezando a quemar, podria ser una sobrefertilización. Te recomiendo regar solo con agua a 256PPM y 6.3pH . ¿Cuanta cantidad de agua? ... La necesaria para que drene por la parte de abajo. A el agua que sale por abajo del macetero le medirás el PPM y si esta entre 700PPM y 1300PPM esta bien, si esta mas alto entonces tienes muchos minerales en el sustrato y debes regar solo con agua de nuevo en el próximo riego, de lo contrario subir la dosis de P y K A el agua que sale por abajo del macetero también medirás el pH y si esta alto en el próximo riego lo haces bajo, y si esta bajo riegas con uno mas alto. Con esa técnica saber los valores de PPM y pH de tu sustrato.

It's using up the nitrogen in the foliage. You also need to up the P in the diet.