I love Pilcher too- Coming Home is a favorite, and I reread Winter Solstice every Christmastime. She's great at domestic fiction.
Dorothy L. Sayers? I'm rather fond of Lord Peter Wimsey.
If you have any interest in Catholicism, then Rumer Godden is good. Five for Sorrow, Ten for Joy is about an English girl in postwar (WWII) France who becomes a prostitute, a murderess and then a nun. Having written it out, it sounds a lot more sensationalist than it really is. I love In this House of Brede. It's about a widow who enters a Benedictine monastery.
Madeline L'Engle wrote some adult fiction, and A Severed Wasp is one of the better ones. It's about a retired pianist who's looking back over her life while also facing new challenges.
Barbara Kingsolver's The Poisonwood Bible gets good reviews, though I haven't read it yet.
The Guernsey Literary and Potato Peel Pie Society is a totally fun and interesting novel written about life on Guernsey during and after WWII. It's an epistolary novel, and really well written.
Laurie R. King's Kate Martinelli series is very absorbing.