The Beautiful Story of Mary is the latest in a lovely collection of books for children from the Catholic Truth Society. As with several others, it is written and illustrated by Maïte Roche. They are suitable for a mother or father to read to a young child, with lively pictures that would, I think, be attractive to the little ones.
Also by Maïte Roche are My Little Christmas Prayer Book and The Beautiful Story of the Bible. A really good book for children who are preparing for their first Holy Communion is Friendship with Jesus, which gives the English translation of the question and answer session which Pope Benedict held with children in 2005 (edited by Amy Welborn and illustrated by Ann Kissane Engelhart.)
If you have young nephews or nieces and want to get them a little present for Christmas, the CTS has some good things for your shopping list.