I think the records will be quite helpful. I asked a researcher to look up my GGG GF's records. ( Henry Hignell, committed in 1886, died in 1892). His records were brief. Poor Grandpa Hignell thought he'd been given a legacy from Queen Victoria, and no longer had to work, but men were following him and trying to murder him and take the money. He became rather violent when told there was no legacy.
If your ancestress was mentally ill, the notes will describe her delusions, wh. or not she was violent. If he died in the asylum, it will contain a record of her hospitalization.
It's well worth a look--I think the post Victorian records would be more complete, and have more detailed notes on her illness and treatment.
One note was rather touching. It said Henry Hignell worked in the garden; was quiet and well behaved. His Father was a farmer who emigrated from Henbury to Newport Mon. I bet he was reliving his childhood, and would have been happier as a farmer or farm hand, rather than a dock worker.