Her father and I have reached the agreement that it's in everyone's best interest to file for divorce. We do not want our young child to grow up thinking it is okay to "Quit" on anything even though it seems like we have quit on our family. She is very close to both of us.
It's best not to go into too much detail with a child of such a young age. Explain the basics, and stress over and over again how much you both love him/her.
It is very hard to explain divorce to a five year old, the best thing to do is to be as honest with him or her as you can. To tell them that this is by far not their fault and that mommy and daddy love them very much.