Teke, I would do that but my mother suffers from serious borderline personality disorder on top of being an active addict. If she comes, the entire thing will surround around her. She tried for years to live through me. If I had the money for every time I convinced myself that it was my day and maybe she'd understand I'd be a very rich women. The bigger deal it is, the more my mother will show how this reflects on her (after all, it is HER daughter that graduated, the one she gave birth to, the child she raised and quack quack).
On top of that, chances are that she actually goes are about 10%. In the meantime I will be rearranging all my plans around dealing with her quacking.
In an ideal world I would let her know in advance, but this is my day and I want it to stay that way.
ETA: I want to thank everyone for posting their thoughts. I took them all into consideration when I sat down to do my cost benefit analysis.
Today I went out and bought my invitations, and mailed the first one to my sister who supports me here everyday.