Op, we had the issue with slats breaking on beds (nothing we were doing - my husband wishes I’m sure!).
I’d chosen a bed because I liked the style of frame- but it wasn’t expensive and it was shoddy quality. Within a year several slats had gone.
i started Googling on Amazon to see if you could get replacement but sturdier slats for existing beds.
I found (on Amazon) fold out metal bed legs/metal mesh for the mattress to sit on, style frames. We had a king size mattress and our old bed frame was obviously king sized too. I bought a double sized fold out frame, unscrewed the central metal pole that went from head to foot and then took out the slats, so that the old frame was just an empty rectangle. Then placed the double sized fold out frame inside the old bed frame. Sounds complicated but very simple!
It has been a brilliant solution! The supporting frame is absolutely rock solid, it doesn’t move even when the 6 year old sneakily jumps on the bed. You can’t see it unless you bend down and peer under the bed and can see we have an extra 6 black legs inside the 4 brass legs of the actual frame.
I appreciate maybe you want to buy them a nice present, so this is not relevant but if they like their current bed frame it may be an option?
We have usually had super king or king sized beds, one of which was pretty blooming expensive from John Lewis and I found that it’s always the slats that go. It seems more of a problem the wider bed you go with. DH is nearly 6’4 and we co-slept for several years so we needed the bed space.
i can find the name of the frame of you like? I think it began with Z….