I agree with Derby. My daughter is only 3 but she definitely knows when I'm not home. When I'm going or staying out of town for a couple days I just say, "Momma has to help/go see some friends/a friend." This applies for when I was going to see Elric and for when I go to see other platonic friends. At 5 your daughter might ask "who" and then you can give a name and most likely they'll be happy with that, especially since they don't understand the complexities of relationships very well yet.
Life is about the journey and not the destination,
so what better way to know life
than to wander all the roads and paths set before you.