(another) Sidebar at bottom, footer at top?

So I have been trying to troubleshoot this problem through existing forum posts but nothing seems to be working. Someone new started posting on the blog and suddenly the sidebar is at the bottom of the page and the footer is floating at the top/middle of the page. Ive checked for extra large images and long urls but its no use. The problem still exists even after I switch themes.

Im guessing that this person must have done something when she posted to mess up all of the formatting but unfortunately I cant get in touch with her and the problem needs to be fixed ASAP.

The url is–> green.curiouspictures.com

For a sample of how its supposed to look check out
https://www.chrismarotta.com/greenblogtest

I know a decent amount of CSS but I am no expert, the fact that it has the same issue throughout multiple themes leads me to believe it must be an issue within wordpress and not my CSS.

Thanks for all of your help and patience, it is greatly appreciated.