Animal Crossing New Leaf is for the Nintendo 3DS, which has a 3-D function to it, that can be used or left alone, controlled by a slider on the right hand side of the machine. Depending on your child's age, it is important to make sure the system is not placed in 3-D mode, per Nintendo's own instructions:
http://en-americas-support.nintendo....intendo-3ds%3F
Secondly, there are a lot of things within Japanese culture that are considered innocent or mild, or okay for children, that you might find objectionable as a Christian. Having never played the game, I cannot speak to specifics, but if you see any mention of things like "yokai", please understand that that is a Japanese word for demons or spirits, as in the game Yokai Watch, which is a Nintendo product for the Nintendo 3DS:
https://yo-kai.nintendo.com/
Also look for words like "tengu" or "kami", as these also relate to Japanese demonology and deities within the Shinto religion.
See:
http://yokai.com
http://www.newworldencyclopedia.org/entry/Tengu
https://www.ancient.eu/Kami/