Surprised no-one asked the OP when they last paid for their 'loved one's" system to be professionally tested and set up a standing order for such tests to be conducted at set intervals over and above those generally considered as adequate.
Yes, a valid suggestion, as maybe yet a further level of reassurance. However, if it is felt that there is a need for RCD redundancy, that perceived need would probably remain even if tests were undertaken fairly frequently (realistically, probably no more often than once or twice per year), since a faulty RCD (which became faulty after the most recent testing) could otherwise remain in service for an appreciable period of time.
Or maybe even considered having 10mA RCDs installed on 'high-risk' circuits.
That's often suggested but one has to remember that an RCD does not limit the magnitude of shock current, and I doubt that shock currents will often be between 10mA and 30mA. In practice, shock currents are likely to be much higher than 30mA, so that even a 30mA RCD will operate. The only real potential benefit is that, for modest shock currents (i.e. not a lot above 30mA), a 10mA RCD should operate a bit more quickly, but even a 30mA is deemed to operate rapidly enough to provide adequate protection.
One also has to factor in the potential hazards that could theoretically result from 'nuisance tripping' with a 10mA device, particularly given the amount of 'leaky' equipment and appliances that are around ... not to mention my personal uncertainties as to how many lives actually have been saved by RCDs, of any I
Δn!
Moving from electric shocks to clearing L-E faults before anyone has a chance to get a shock, I again very much doubt that a significant number of such faults result in a fault current under 30mA. Indeed, such a fault current will commonly be thousands of times higher than that (which is what we had to rely upon, for ADS, before we had RCDs).
Kind Regards, John