To be brought up bilingual is a rare gift, but like most gifts in life, it isn’t always plain sailing. And when it comes to reading, it’s double the trouble, and double the fun, but also, sometimes, double the work.
You may find that your bilingual child or pupil has a preference for one language over the other; you may find that they often mix the two. You may find that the learner speaks one language with one caregiver, and a different language with another.