To see the parent/child relationship you could install "htop", which displays in the console all processes in a tree-like structure, or run the command...
Code:
ps -Al | head -n 1 && ps -Al | grep X
...which will display the information for all processes called "X" (in your case you might have to replace the "X" with "Xorg" - don't know how your process is called). You could get an output similar to this (this is not my real output - just to show you):
Code:
F S UID PID PPID C PRI NI ADDR SZ WCHAN TTY TIME CMD
4 S 0 3775 3774 0 74 -1 - 20286 - tty7 00:02:25 X
4 S 0 3776 3775 0 74 -1 - 20286 - tty7 00:02:25 X
Here you see that the X-process with the PID 3776 has as PPID (Parent PID) the one with the ID 3775, which is as well an "X"-process.
And about the memory you see that is allocated: in Linux many processes share the same memory, which could mean in your case that it's not that you get those 64MB allocated twice, but that both X-processes are sharing a single 64MB amount of RAM. I didn't understand yet how to find out if a certain amount of RAM is shared or if it isn't...