Ok why is this girl doing this to me?

Alright every morning at homeroom we have time to fill up our lockers and put books into our book bags. I have 2 book bags because i have a foot problem were i walk slow and my feet hurt after walking for awhile ( you have to walk alot in my school) so i have 2 book bags 1 is for my morining cles and my other one is for the afternoon cles. I take some extra time to fill up my 2 bags. Everytime when i am filling my bags this one girl in my home room comes up to me and says "Wow...You have 2 bookpages....Thats sad.." I keep telling her about my foot probelm and its just a stragey i use, im not a person who hates lockers it just saves me time for i can go to my next cl without my feet keeping me down. She says this 2 me almost everyday and when im in the hallway and i see her she gives me a look or she whispers something to her friend. Why does she do this?