Never saw the movies or read the manga with her in it?

From Bulbapedia:
[i]Latias ruffles its feathers and cry loudly when there is hostility toward it. Its downy feathers can enfold its body and refract light, which allows it to become invisible or alter its appearance. It can also use its down to use its signature move, Mist Ball. It is highly intelligent and can understand human speech. It is capable using telepathy to communicate with others. In the fifth movie, Latias had the ability "Sight Sharing", which allowed Latias and people around it to see exactly what Latios was seeing.

In the Pokémon Adventures manga
Latias, along with Latios, was befriended by Emerald and took the young Trainer to the Battle Frontier. It has appeared as a human a few times as the saga continued by using its ability to reflect light.[/i]