Urban fantasy: The Broken Heart, Oklahoma series by Michele Bardsley, with titles like I’m the Vampire, That’s Why and Don’t Talk Back to Your Vampire. The premise is that a vampire bites a bunch of people at a PTA meeting.
If by “soft sci-fi” you include alternate history, The Yiddish Policeman’s Union by Michael Chabon.
Paladin of Souls is also slyly humorous. It’s my favorite, and I’ve read everything Bujold has written.
I missed the part about “soft sci-fi”. In that case, try all of Bujold’s “Vorkosigan Saga”. It’s sort-of Space Opera, but focuses more on intrigue than giant battles, although there are a few battles to be had. It starts off as a “meet-cute*” story between two middle aged characters, and then goes through their family development as they have a kid, and the kid eventually grows up to be his own person and have kids of his own. There’s a few side novels as well set in that universe.
*For liberal definitions of the term “meet-cute”.
Maybe no one reads her anymore: Andre Norton: Moon of Three Rings and associated books.
I also like Marrion Zimmer Bradley though she’s not for everyone.
Misty Lackey:
The Elemental Masters – I especially liked The Wizard of London and its Sherlock Holmes sequels
Diana Tregarde
Pat Wrede:
The Seven Towers
Mairelon the Magician and its sequel
Barbara Hambly:
The Darwath Trilogy
Sunwolf & Starhawk series
The Windrose Chronicles
Elizabeth Bear:
New Amsterdam
I’ll second both of those.
Definitely!
I would have added that one too, but it’s definitely what I would call military sci Fi. Not as hard as it could be, but with wormholes, military fleets and extreme genetic engineering, among other things. It’s also pretty rapey.
Still my favorite anything of all time.
I read several of her books when I was younger, and enjoyed them. In recent years (well after Bradley’s death), her daughter went public with accusations of sexual abuse and pedophilia against her and her father, and that has definitely damaged Bradley’s reputation and renown among fans.
Ben Aaronovitch’s Rivers of London series featuring policeman Peter Grant seems to be classified as urban fantasy. I enjoy them.
Not a series, but Silverlock by John Myers Myers is an excellent read.
Well, the Witches series in Discworld.
Always a good choice!
Yes, they nicely combine fantasy with British Mystery and Police procedurals. You get all three for the price of one.
Truly great read.
I liked Silverlock too. Maybe it’s time for a re-read.
What about the Gentleman Bastards series? The Lies of Locke Lamora? It starts out with him as a kid IIRC, but it’s mostly a cool fantasy world featuring an adult man who is fantastically good at heists. I didn’t read all of the first book because I get distracted easily, but I really enjoyed what I read!
My recs are for urban fantasy, because that’s what I know.
If you don’t mind a self-rec, my Alastair Stone Chronicles series features a protagonist who starts out in his early thirties and grows older from there (chronologically, anyway–but no spoilers! 
) My Calanar and Happenstance and Bron series also feature adult protagonists.
Other recs, if you don’t mind indie writers (many of whom are very good):
The Arcane Casebook series by Dan Willis (set in the 1930s, excellent)
If you don’t mind a little light romance in your urban fantasy, the Ravensblood series by Shawna Reppert is good.
For trad stuff, the Dresden Files is a really good series (if you don’t mind the fact that Dresden can be an annoying horndog sometimes).
I really enjoyed the first book, but yeah, it has a slight veneer of “lovable old fashioned sexist” to it.
Ursula K. Leguin wrote a lot of soft scifi/fantasy, beyond the Earthsea stories, that is very much for adults (in a good way). The Lathe of Heaven, The Left Hand of Darkness, and a YAish novel The Beginning Place are especially good.
Robin McKinley made a cottage industry of reimagining fairy- and folk-tales. Deerskin is a standout but Sunshine is probably more along the lines of what you are looking for.
Patricia A. Mckillip is more of a pure fantasy writer, but she does a great job of world building, which makes her novels stand out from the run of the mill fantasy books. I found The Riddlemaster of Hed and the rest of the Riddlemaster trilogy to be a compelling read.
Holy cats, I say “if you don’t mind” a lot in my post! 
Caught in Crystal - one of Patricia Wrede’s books set on Lyra, has Kayl as the protagonist. She’s a mid-thirties widow with 2 children.
There are Nathan Lowell’s Tansy Fairpoint books. She is 50ish. I found her a bit of a doorknob.
I guess I don’t mind. I didn’t catch it!
T. Kingfisher (Ursula Vernon) has some books with middle-aged protagonists. I’m having trouble remembering exactly which ones.
Some of her fantasies are fantasy/horror, so check before you read if that’s not your thing.
Holy shit, I had not heard that. I was aware of the man hating stuff, but not THAT. I don’t know how to feel about books I’ve really loved. That poor woman (Greyland) and all those kids.