Based on the limited info and pictures supplied it could be anything.
I'm going to guess and say that the dark shiny leaves with burnt, clawed tips
suggests N tox & or over watering. I don't see any perlite in the soil mix &
it looks awfully compacted, what is in it & what are you doing for drainage?
And how about your light? What power and percentage and height above
canopy. Also, how old is she and how often are you watering and fertilizing
and @ what age did you start? How about RH?
If the leaves are somewhat straight out or pointing up a little, the light is @ a
good height. If leaves are pointed up @ 30-40 degree angle and "praying"
means they want more light. If extreme "praying", taco-ing or drooping
down as if to cover up and protect themselves = too much light - in which
case raise the light &/or reduce power if you're able to.

Farm?