Is she in an air conditioned room?
I think it may be best to wash and fill the water bottle daily.
The running balls aren't recommended for chins, it gets to hot.
If she is enjoying her time out, she probably doesn't back in the cage.
Toys and ledges in her cage may help
Her nursing in that position could be a big reason for the smoodge and possibly could be that she expressed her own anal gland.
Also if she had pyo or infection the kits would not be thriving.
Could/would this work or way to over the top
Pellets can be zip locked and frozen. Yes or no
Could you store hay in vacuum sealed bags to stay fresh.
Can a chin have fresh sprouts as a treat