Your colleague sounds like a fucking headcase. Tell her to butt out, CF.
I have had five surnames!!! The one I was born with (my dad's), my mum then gave us her second husband's surname when she remarried, which I had for 10 years, stepdad was a violent arsehole and I was his punchbag, I had a nervous breakdown because of the abuse aged 16 and when I was 18 (mum had split with him 2 years prior) I went out and changed my surname by deed poll, my real dad had barely been in my life and I didn't want any link to my step dad, so I changed my surname to the surname of a famous rock star!!! (It's nothing outlandish, a real surname, not common, but only fans of the band would recognise it).
Fast forword 10 years, I got married, wanted to keep my chosen name as there was such a big reason to what I endured and why I changed it. DH was unhappy, so I compromised and double-barrelled it.
My double-barrelled name is soooo unusual that I'm the only one in the country!
Taking us to today, I work in radio and magazines now, as a presenter and writer. My real name is such a mouthful and also many presenters use a different name because of stalkers, so I use my mother's maiden name for my media work, but my real name for everything else. 
So yeah, back to your post, do what you like and ignore everyone else. It's nobody's business.