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Yes, the Children's Crusade was indeed associated with this event you were asking about. Most of the crusaders during this "crusade" attempted to go to the Holy Land by way of the port of Marseilles, France -- very close to Spain. The Almohads meanwhile molested these "crusaders" -- and the result was the knights' battle against the Almohads.
Upvote:4
In order to actually keep the territory they won on the battlefield, and to move on further south, the Christians would have to take the castles and fortified towns in the area (as was mentioned in the comments). After the Battle of Las Navas de Tolosa, this specifically meant Baeza and Úbeda.
Shortly after the battle, the Castilians took Baeza and then Úbeda, major fortified cities near the battlefield and gateways to invade Andalusia.
So how soon was "shortly"? Not actually all that short, except perhaps by historical standards: 15 and 21 years later respectively.