2D Project Question- Ellen standing on air

Hello.

I'm just starting to learn Unity and I'm taking the beginner 2D course to build my skills. This is my first post on the forum, so I'm sorry if this issue has been brought up or if I'm supposed to seek answers elsewhere. Basically I'm having an issue where Ellen is standing on air. What is best way to correct this? How I can I determine if there are some "invisible" objects to look for. Below is a screenshot.



**** Update. I selected TilemapGrid and found 2 lines where she was standing. I tried to get rid of them with the eraser but they are still there. Any ideas what could be going on? It is in the scene view of the game. Thanks.