I don't think it's colloquial.

@@ -19 +18,0 @@
-<misc>&col;</misc>

Not really sens.

@@ -19 +19 @@
-<misc>&sens;</misc>
+<misc>&col;</misc>

Daijisen

I think it's similar to "mental hospital" vs "psychiatric hospital"
"mental hospital" is perhaps an outdated term, hospitals will not put that in their full official name anymore, but it is in the vernacular and people use the former term and will keep using the former term for a long time. even if the term is avoided in official contexts.

or perhaps a more apt comparison is "fireman" vs "firefighter" ?

I expect people will be using 看護婦 for many more decades to refer to nurses.

@@ -21 +21 @@
-<gloss>(hospital) nurse</gloss>
+<gloss>(female) nurse</gloss>

GG5: a (hospital) nurse. ▲現在は「看護師」と呼称.
All the JEs point to 看護師 as the current term

I'm adding a temporary "deprecated" note. I've proposed a misc. tag for it.

@@ -20 +20,2 @@
-<gloss>(female) nurse</gloss>
+<s_inf>now deprecated</s_inf>
+<gloss>(hospital) nurse</gloss>

看護婦の呼び方はいつから変わった？ 「看護師」と「看護士」正しいのはどっち？
https://kango.mynavi.jp/contents/nurseplus/workstyle/20211012-2138748/
しかし、2001年の法改正で「保健婦助産婦看護婦法」から「保健師助産師看護師法」に名称が変更されたことにより、翌年2002年に性別による読み方の区別が撤廃され、男女ともに「看護師」と統一されるようになりました

「看護師」という表記が基本となってから約20年経過した現在も、未だに「看護婦さん」と呼ぶ人がいたり、ネット上で「看護婦」「看護士」と称されていたりすることがあります。しかし、医療業界では「看護婦」「看護士」という表記が使用されることはほぼありません。

You might consider administratively removing [news1], though if [ichi1] stays, this word will remain "common" (on sites like jisho.org). 

I think "deprecated" was a good description.  In any case, I think *something* should be said, and [sens] might be correct. It's about respect for the profession and for Japanese workers. My Japanese textbook was published in 1987 and used this term.  By 2015, my late-30s native Japanese (female) teacher corrected the class, and told us to use 看護師 instead.  The ref'd article suggests the legal designation stopped using this term in 2001.

看護師 is used in all professional contexts.  It was how I was told to address the nurses at my vet. I've said 看護婦 on accident when reaching for a word, and it was actually a little bit embarrassing.

Right now this word shows up as "common" due to statistics, and is an analog for a common English word still-in-use.  I think this merits some kind of warning. Old Japanese people may still say 看護婦 out of habit, but It seems that foreigners should prefer 看護師 in almost all cases.

As mentioned, the [news1] stat itself is obsolete.  If mainichi shimbun vocab were collected today, 看護婦 would certainly not make the cut.  

Here's a government publication with a list of potentially discriminatory words.  This one is on the list:
https://www.city.takarazuka.hyogo.jp/_res/projects/default_project/_page_/001/021/755/sassi19.pdf

(granted, it's swept up some still-fairly-common gendered vocabulary)

@@ -18,0 +19 @@
+<misc>&sens;</misc>