Get the original 1609 Douay-Rheims!! hahah, just kidding…
It depends on how old your niece is, If she’s around 6 or 7, I strongly recommend you get her a children’s bible like…
“My First Catholic Bible”
it takes excerpts from the New Revised Standard Version- Catholic Edition and has colorful pictures that are NOT cartoonish.
It has a reading schedule, at the bottom of each page has a verse to memorize, and has a page with prayers like Our Father, Hail Mary and Glory Be!
It also has an Imprimatur
you can buy it
HERE
If you want her to have a complete Bible,
I say the Contemporary English Version is the easiest overall, however the Good News is really easy too…
=========================
Genesis 1:1-3 (Good News)
" 1 In the beginning, when God created the universe, 2 the earth was formless and desolate. The raging ocean that covered everything was engulfed in total darkness, and the Spirit of God was moving over the water."
Genesis 1:1-3 (Contemporary English)
" 1 In the beginning God created the heavens and the earth. 2 The earth was barren, with no form of life; it was under a roaring ocean covered with darkness. But the Spirit of God was moving over the water."
John 1:1-3 (Good News)
“1 In the beginning the Word already existed; the Word was with God, and the Word was God. 2 From the very beginning the Word was with God. 3 Through him God made all things; not one thing in all creation was made without him.”
John 1:1-3 (Contemporary English)
“1 In the beginning was the one who is called the Word. The Word was with God and was truly God. 2 From the very beginning the Word was with God. 3 And with this Word, God created all things. Nothing was made without the Word. Everything that was created received its life from him”
However if she’s around 15 or older, I would suggest the New Revised Standard Version- Catholic Edition or New American Bible. Its better to have a “more accurate” Bible but still easy to read