5 year old

?Nicole? • I`m 26, i have a 5 year old daughter named Bailey & she is my sunshine, Single, but god is busy writing my fairytale ?
I plan on telling my 5 year old daughter this weekend about having another child I'm not sure that she will quite understand, how can I explain it to her to where she understands or should I explain it to her more the farther I get along?