This happened to a Janome I had....Elna, same machine...You can take the pedal apart...but you have to do it carefully.
I did. I unscrewed it, took it apart on a white bath towel so any screws would fall onto it. If you move anything else inside to get the lint out, (I used a little brush)...take a picture of what you are removing and from where..... it is pretty simple. If you have had the pedal on a carpet or you have pets...it is probably fuzz or pet hair. My worked fine after removing the lint. If you have another Elna, New Home or Janome pedal, they would fit. I wouldn't spend $200 on a machine that is 34 years old, unless it was a Singer FW. Best wishes and what fun, sharing with your granddaughter. I know you will have a great time.