In the tips and notes, kama was used without -ki-, with -ta- in both clauses. Is this doubling up possible to? Is kama there for emphasis?
As a teacher I find this sentence really disturbing. It should be "Kwa sababu tunahitaji kwenda shuleni, tutaamka kabla ya kukamua ng'ombe".
We would not say this in English as it suggests we might NOT wake up. We would rather say: WHEN we wake up, we will go to school