Pen names

I am currently tossing up whether or not to use a pen name. On the one hand, it would be good to have a separate writing identity for social networking, publicity and such. On the other hand, I want to see my name on my work. I want my kids to see their surname on my stories, and be able to be proud of that.  The solution I'm considering at the moment is to use  "Mary Jones" on the historical romance stories and any contemporary stories, and to add in my birth name for the SF works - which is my first love and the area I am most strongly working in now.
So I would write SF under the name "Mary Brock Jones". There is also plenty of precedent for such names in the SF community - eg Lois McMaster Bujold, Orson Scott Card, Marion Zimmer Bradley, Vonda E McIntyre, Ian M. Banks to name a bare few. SF writers seem to revel in having a trilogy of names. So will see how it goes.
To start with, I have entered an SF short film script in a competition under Mary Brock Jones as a Pen name. Here's hoping it is a lucky choice.
As for my year's plan, my RWNZ Clendon entry is finished and nearly printed out ready for posting off.
So I'm still on track - sort of. One tick down, two more big ones to go for the year. So one pat on the back.