The problems they had during this period were not constant, nor were they capable of pushing them to their limits. They were enough to worry them and force them into action several times, but they also had time to 'enjoy' the journey across the Sea of Stars.
Vicente, in particular, took advantage of the months of travel to talk to Lyra about many things, learning what she knew about the Sea of Stars and the Nine Paths.
She didn't know as much about these two subjects as the Fairy King and some of the Fairy Tribe elders did. But she had different information and opinions from those Vicente had already come into contact with.