What were the first chapter books you enjoyed reading aloud with your DCs?

If she likes something slightly old-fashioned, I can recommend Teddy Robinson Stories (Joan G.Robinson), The Adventures of the Little Wooden Horse (Ursula Moray Williams), the Mary Plain books (Gwynedd Rae) and Winnie the Pooh!

DD is 4 and loves any Roald Dahl, some Enid Blyton (Faraway Tree and Naughty Amelia Jane are her current favourites), just finished My Naughty Little Sister and she liked the Narnia series. Largely, her library is my library from infancy so it's like reliving my childhood.

She still loves picture books as well but reads them to herself.

Lots of those above (Clever Polly, Gobbolino, MMM), and also:

Little House in the Big Woods (Laura is 4 at the start, and has her 5th birthday during the book - the later books are more for older children)

Anna Hibiscus series by Atinuke (I liked this one as - like MMM - each chapter is a separate story, so ideal for bedtime reading, it also has very good illustrations)

With dd1 I did very similar to you and then went onto Famous Five when she was similar age and after a couple of those did The Lion The Witch and The Wardrobe. Tried Prince Caspian (because she wanted to) but found it not as interesting, so tried Arthur Ransome, which she loved, and Elizabeth Goudge (Little White Horse among others) and I think we did a couple of Noel Streatfield (Ballet Shoes is her best known) before she decided she'd rather read to herself.
Dd2 had a totally different taste. She didn't like the chapter books above read to her, but she loved reading them herself. She liked old fashioned stories, preferably with a princess in disguise or pony stories. Wish for a Pony (Monica Edwards) is actually quite hard to read out loud but she loved those ones, and I can't remember the author's name (Viola Needham???) but she wrote The Black Riders and House of the Palidin.
Ds (age just 4) would prefer me to read a technical book on the merits of various military aircraft. Don't know how much he understands, but I've sure learnt a lot. He does quite like Famous Five, I'm currently reading him The Castle of Adventure (another Enid Blyton) and has anounced his wish to own a parrot. He's just chosen to buy a book called "How to look after your parrot." He won't get to put it into practice.

She is still very young,I would also still enjoy books with pictures.