The way I understand it, GRRM did not have a complete Targaryen family tree until he worked on The World of Ice and Fire (published in 2014). Until then we had disjoint information about the Targaryens of the past but nothing concret to link them all. I stumbled on two sentences in the books published before TWOIAF and I was wondering how/if we can reconcile them with the current canon established in TWOIAF (the retcon for Jaehaerys I's children from Fire & Blood does not matter here).