Earlier this year Pope Francis decreed that "July 29 be designated in the General Roman Calendar as the Memorial of Saints Martha, Mary and Lazarus."
Previously July 29 was reserved for St. Martha alone in the Roman Rite.
One of the reasons for this was uncertainty in the Roman Rite of whether Mary, the sister of Martha, was Mary Magdalene.
This is also why St. Martha's feast is so close to the feast of St. Mary Magdalene. Vatican News explained some of the feast's history.
Yet, recent scholarship has separated these two "Marys" and now distinguishes Martha's sister as "Mary of Bethany."
Interestingly, Orthodox Christians have celebrated these siblings for many centuries on a single feast.
The June 4 feast is entitled, "Righteous Martha and Mary, the sisters of Lazarus."
Technically Lazarus has a separate feast on October 17, and is also featured on "Lazarus Saturday" before Palm Sunday.
As a result, Pope Francis' new feast is actually a return to tradition, honoring these special friends of Jesus who welcomed him into their own home.