I would put a platform in the larger one. They do seem to really like having a shelf or platform to sit under and to climb onto and it saves being limited to floor toys. This one is a good size and quite tall (21cm) so would sit above quite deep substrate. Agree with Cypher about giving her more substrate.
Or - do you have space for a detolf instead of the two bin cages? Continuous floor area gives more scope for enrichment and they can push stuff around more! It becomes like a terrain.
https://www.amazon.co.uk/Trixie-Natu...living+shelter
It would cost £40 for a detolf and I'm sure you'd have no problem making lids for it if you've made bin cages
It would need something to stand on - I think the cheapest option there is two lack tables (£5 or £10).
Her bins look nice, but if you are looking to give her more enrichment, then personally I would invest in one larger cage rather than more items for the bin cage. Something like the Barney cage (if not the detolf) as it already has a good house and a platform and loads of space for all her current toys. Plus you can hang things from the roof.
This was our Syrian's set up in his Barney cage. One larger floor area also gives space for larger toys like a large cork tunnel which is also something to climb over as well as tunnel and a natural texture which they sometimes seem to like. I had a vine branch in his previous cage too which added enrichment (second photo).
