Short term memory or down right lie?

Last night I was watching a tv show in bed and Miranda came in. It was about 8:40 which means she was up pretty late. She said that she felt something sticky behind her ear that was bugging her and she wanted me to look at it.  I took a look and sure enough there was this very sticky feeling behind her ear.  Then I looked at her hair and there was pink stuff in it.  It looked like gum so I said, Miranda, did you have gum today?  Miranda responded, "well...I'm not sure."  I said, "Miranda you have gum in your hair. Didn't you say you had gum on your playdate?"  Miranda then said, "Oh yes."  So I asked her how she got the gum in her hair and head. I asked her if there was gum in her bed...as if she fell asleep with it in her mouth.  She said no.  So as I was cutting the gum out of her hair, I again I asked her how this gum got in her hair. She said she didn't know.  I told her that wasn't an ok answer and she had to think about how this happened.  That is when she said, "Will I get in trouble if I tell you?"  I told her no and she answered:

"Well...I'm not really sure, but I guess it could be from when I stuck that piece of gum behind my ear at Lily's house.  I really wanted a snack, but I was chewing gum, so I put it there."