It sounds a little clumsy. If rewriting is an option I'd be inclined to put "Her husband had recently died and I found it difficult to ask her about him"
Just my opinion of course!
The sequence and choice of words is fine, but just put a comma after 'husband' and it will read more naturally. We would pause briefly after 'husband' when saying the sentence. The comma indicates that pause.
Imagine that the sentence continued 'but I did'. Would it sound correct then? It would, because that's how people speak.(You'd need two commas then; one either side of 'who had recently died' )
Personally I'd have just shoved a comma in after "husband", since I'd normally pause there were I saying it, since the information that follows is additional and the sentence still make sense were it not there.
Just a question; why would someone want to ask about someone's husband if he'd died? You can't ask; how's your husband? Surely the sentence is I found it difficult to talk about her husband, who had recently died.
"I needed to get a complete family history of diabetes, and asked about her parents, but I found it difficult to ask her about her husband, who had recently died."