Median Trouble

The paper says "find the median for a list of 18 numbers".  Not feeling very sure of the help I could give Riley, I honestly tell her "I'm going to check the computer", where I find that you list the numbers in the order they go and find the middle.  If you have an uneven middle, you are to add the two numbers together and divide by the number you have and you'll get the "place" of the number which is your median.  But Riley strongly disagrees.  Although her numbers range from 28-53 she thinks the median is "8"...to which I cannot convince her that the median is one of the numbers in your data.  She says "That is not how my teacher taught us this today!"  Being supportive (*not) I write in pen next to her answer "Riley and I don't agree on this one"..and that being said, I walk away.  She still is adamant that her answer is right, me too.  I know that when she gets to school, her teacher will sort it out.  I just have to have my opinion on the paper.  When will I learn to just let it go?  That is what I am trying to teach her afterall.  I know that I am not the best example to follow. She just wants to "check it off her list" that her math homework is done and not look back, not correct or discuss or adjust.  Hmmm, who does that sound like? Yes, me!  Oh well, another day!