Am I being unreasonable where books are concerned?

Some childrens books can be sold on eBay, check them to see if they are worth any money in Completed Listings, you can then see how much they sold for.
TBH most childrens books don’t sell and unless they are in very good condition or the drawings are by well known artists the Charity shops can’t sell them either, but some shops can sell them to traders in large bags, but they don’t get much nowadays.
I think the ‘free books’ by the gate is the best idea.

My local charity shops regularly put out appeals for books as they don’t get enough donated, so I wouldn’t take your DILs word for it without checking your local shops.

I'd haul a suitcase at a time out onto your front wall, with a sign saying "free, help yourself" and hope that they bought someone else pleasure, as they did you.

You could try a site like this www.webuybooks.co.uk/?gclid=EAIaIQobChMIwKLMl-X4-QIVXoBQBh2DkAiVEAAYAiAAEgJ8rfD_BwE or www.musicmagpie.co.uk/sell-books/

others are available.

All Oxfam shops accept second hand books www.oxfam.org.uk/donate/donate-to-our-shops/donating-books/

You could ring some of the book dealers in Hau-on-Wye and ask if any are interested, although with that few books, you’d probably have to take them there if there were.

There may be a local second hand dealer who would be interested?

You could put therm out in a box in front of your house with a note saying ‘free, help yourself’.

My local GP surgery sells books to raise funds for carers and young mums groups.

It’s taken forever to type this - too many interruptions - so apologies if I’m cross-posting info.

I have no answers but I am in exactly the same situation.My books date from the fifties and have been read by my daughter and elder granddaughter but they are really so dated that I can’t see anyone wanting them. I have investigated a few outlets but nothing came of them.I am keeping back a few of the ‘classics’ like Heidi and the Katy books for the younger grandchildren but don’t know what to do with the rest.
Also we have two lovely old family bibles but because they are not in pristine condition they are of no value and future generations of our family would not appreciate them. I don’t know whether I could bring emyself to burn them but they are taking up a lot of space.

I am no authority but I once made a marketplace account on Amazon with my son and sold books that way.
Also another son lives in Glasgow where they have a Fb book swap group.
Gumtree ppl may also swap books locally.

Children’s books are expensive! Why not do a car boot stall and sell them? I’m sure there will be plenty of takers.