Keep in mind, only Heather said she identified ELIZABETH'S shoes. Nowhere did LE state that Lyric was identified by her shoes.
These girls would be treated as 2 separate "instances" when it comes to the families (I hope that makes sense).
They wouldn't have taken both Lyric AND Elizabeth's shoes to Heather to identify. Someone from Lyric's family (even though they are still family) would have been taken to probably Misty or Grandma to identify any clothing of Lyric's (if it was found at the scene).
Thank you for the correction!