@Lucy961 I think you need to read what Aircover actually does/does not cover. For one it is not an Insurance policy (except for the liability bit) so it is unregulated.
Basically Aircover for guests is pretty useless as it usually just delivers what Airbnb is required to deliver by law anyway.
We are required by law to have both liability and damage insurance, of a type specifically tailored for STRs. This would cover any liability to the guest (e.g., guest suffers loss, injury or death).
As @Mike-And-Jane0 point out, "Aircover" is not an insurance or guarantee, so it's important to have actual insurance coverage. In our case, it's required by law.
My insurance company added an addendum to my policy called "home sharing".
Home sharing insurance
protects hosts who let visitors stay in their principal residence or a portion of it on a temporary basis for fewer than 30 days at a time. If this your scenario, shop for home sharing vs small business insurance.
I just came across your post and noticed the advice from our Hosts. Have you had the opportunity to read the >>>Aircover guidelines? As Elaine mentioned, it might also be worth checking what the local authorities in your area require.