It may be that she has a deep ear infection that is impacting her hearing. This may also be making her feel 'down' and that is the reason that she is going to the bathroom floor to be quiet.
I think you need to have her in to see the vet to see if there is anything you can do to make her feel better.
The breed does have a hereditary defect of progressive deafness. You can read about this here
http://www.cavalierhealth.org/deafness.htm
another possibility is a mucous plug in the ears which you can read about here
http://www.cavalierhealth.org/psom.htm
You need to see your vet with your pet and talk to him about the hereditary diseases as well as plain old ear infections.
If your dog is deaf there are training methods to work with her to help get the two of you back in good communication. This site and many others can give you good ideas on how to work with her if she is deaf
http://www.deafdogs.org/
Hope this helps you!
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