iMac 3.06 GHz Intel Core i3 - Running slow

Howdy!

I'm having a difficult time diagnosing what exactly is causing my grandmother's iMac to run slower than usual. More specifically, I have to click multiple times inorder to get anything open, this includes links on Safari or Chrome and OS X UI items. It's just being unresponsive most of the time.

Hardware:

- OS X 10.9.2

- 3.06 GHz Intel Core i3

- 4 GB 1333 MHz DDR3

She has a steady Memory Used of 2-2.5GB out of 4GB running without anything obvious opened. Which seems high.

All she does is check email, browses the internet (single tab), and plays on pogo.com (which I think is Java). Definitely something this computer should be able to handle.

Activity monitor shows a bunch of of open processes, but I really don't know what's normal... Here are 2 SS of both the CPU Usage and Memory Usage.

So short of upgrading the memory, which probably would help, does anyone see anything odd or have any suggestions on what I could do to help speed this thing up? Or notice anything in the screenshots that seems odd?

I do occasionally open terminal and purge, which helps a little, but it doesn't take long for the issue to recur.

Thanks!