Am so f-ing cross at work colleague....

[mojoawol]

who, on a rare night out for drinks with them and when I said that DS(just)4 sleeps in my bed, told me 'I really ought to get him into his own bed, he needs his independence'.
AAAAAAAAGGGGHHHH - still want to punch her smug, child-free face. What business is it of hers? Not to mention he has probably had plenty of independence since I went back to work full-time when he was 1, and then shortly after split with his father. Christ, am getting cross again just typing about it.
Is my only hope for revenge waiting until she has her own kids to even have an inkling?

To be honest this has nothing to do with the status of relationship between the two people and everything to do with disapproval from someone of someone elses living arrangements.

It is judgmental and based on no evidence as the OP has made clear. For those reasons alone I see why it is annoying.

Mollie - if you (either as friend or colleague) said to me that you and your (if you had one) DP were sleeping in separate beds, would the correct response be 'you need to be in the same bed, you need to have that closeness' (or similar) without knowing any of the reasons/background?
Thought not.
The point is, I wouldn't expect anyone to jump to a judgemental stance like that without even knowing or bothering to find out situation. Even then, it would still bother me.

being told I really ought to do anything would get my goat

I would irritate me a little but I'd not have shared that bit of info TBH as people do tend to have strong opinions on it. I co-slept for a long time with all of mine - they still come into my bed now from time to time. And some people think it's the next thing to child abuse