Thank you for confirming. I highly doubt you will be implicated for anything. Given that the post-mortem has taken place, she has been buried and the coroner has indicated cause of death then from their end the matter has concluded, however, if they are provided with further information - such as the history of violence, then they will consider whether there are grounds to reopen the matter and undertake an inquest.
I would suggest that you contact the coroner to report the history and they will be able to advise whether they have ground to pursue an inquest.
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