Will my 3 year old child ever desire to learn her ABCs and 123s?

We have a 4 yr old who soaks up books and is already advanced in her preschool cl. Then we have a 3 yr old who is determined not to learn her letters and numbers. I'm truly worried that she's going to grow up illiterate or flipping burgers. We read to the girls every night and try to get my 3 year old to learn. Will her learning switch ever flip to on? Help!