Messaging the widow of a colleague who died

[Paraguay]

probably about ten years ago. He was tremendous and we were in a department of two.
I didn't know his wife but met her after he died and she was lovely.
occasionally I think of writing an email to say I hope she's ok and I chuckle occasionally when I find emails from him and we all think of him a lot.

would this ambush her? Would she like it or is it a bit selfish of me?

Not an ambush at all. Perfectly lovely and normal.

she can smile along, reply and engage or not.

I did same with a colleague’s wife. She now lives next to my good friend and we often remember funny stories.

I’d say do it. Tell her you think about him still and give her an example of a memory you have of him. I don’t think it’s selfish at all (I’m a widow btw and I’m always happy to hear from friends and colleagues)

Perfectly reasonable. Things like this were comforting for us as a family as it meant that he hadn’t been forgotten.

My late-dh died 9 years ago, I'd appreciate receiving such an email.

Re ambushing - lots and lots of things make me think about late-DH, it isn’t every day any more but it is certainly every week. Such an email would just be another such thing, but lovely.