just investimagated and mmcblk0p2 should indeed link to /home partition, so if you installed nitdroid on /home then that is correct. Some people have it on mmcblk1p2 (this must be the sd card) mmcblk0p5 (if you installed it on a separate partition) and I've seen others as well.
If the command doesn't work for you then you just need to dind out here it is installed to on your system.

Basically, It is in mmcblk0p2 try to mount