So near and yet so far.

An idea takes form.  River decides that she simply must get behind the entertainment center.

Okay, the box is slightly unstable...

Uh, make that very unstable.  Good thing Simon is searching for an alternate route!

Failing in finding an alternate route behind the entertainment center, Simon attempts to scale the box after River gave him a "You try it!" look and a nudge on the rump.  He noped on out of there fairly quickly once the box started moving under his paws.

River decided that if she wanted something done right, she'd have to do it herself.  Unfortunately, once her tenacity paid off for climbing onto the first box, she realized that the second box was slippery and her chin was the only thing that would ever get onto it.  I ended up rescuing her from this little balancing act.
She hasn't given up on her dream--she's still plotting to get back there one day (if the constant looks she gives the entertainment center are anything to go by).