Get TeamViewer, it's free for non-commercial use. You both install it, launch it, she gives you her ID and password. It's pretty easy to use.

All depending on the hardware combo I have found the recent version to have some quirks sometimes with double-clicks, but that's always accomplished by Command-O. You can set it to start at system startup if you need to do restarts and want access right after the restart. It always gives the same ID number when it starts but generates a new password. You can also lock in a secondary password for unattended access.

It gets through any router/modem, no need to mess with port forwarding or anything.