According to the Catholic Church, are Adam and Eve in heaven? According to this site


  As we have said elsewhere, Adam and Eve are not called saints in
  ordinary reference, historical or scriptural. But they may be called
  saints on their feast day, which is the vigil of Christmas, because we
  know from sound Catholic tradition that they repented of their great
  sin, lived lives of holiness and are now in Heaven.


What Catholic tradition speaks of them to be in heaven?

I’ve read (and since I cannot remember where, there is no reason to put any credence to the following statement:) that Adam and Eve will stay in Purgatory until the final soul is purified.
What Catholic tradition speaks of them to be in heaven?


This is the doctrine known as the Harrowing of Hell. It says that, after his crucifixion, Jesus descended to the realm of the dead, in order to bring forth the righteous who had died into the Resurrection life. "He descended into Hell," as the Apostles' Creed says.

The doctrine is that the righteous were freed by his Resurrection, and "opened heaven's gates for the just who had gone before him" (Catechism of the Catholic Church, 637).

There is an ancient homily for Holy Saturday (quoted in the Catechism) that mentions Adam and Eve by name:


  Today a great silence reigns on earth, a great silence and a great stillness. A great silence because the King is asleep. the earth trembled and is still because God has fallen asleep in the flesh and he has raised up all who have slept ever since the world began... He has gone to search for Adam, our first father, as for a lost sheep. Greatly desiring to visit those who live in darkness and in the shadow of death, he has gone to free from sorrow Adam in his bonds and Eve, captive with him - He who is both their God and the son of Eve... "I am your God, who for your sake have become your son... I order you, O sleeper, to awake. I did not create you to be a prisoner in hell. Rise from the dead, for I am the life of the dead."


This is also a theme in religious art. For example, Bartolomeo Bertejo's painting Christ leads the patriarchs from Hell to Paradise (downloaded from Wikimedia Commons).