Our old BT passed away about a month ago now. Like yours she was 14 but had the best life.
We were insured with animal friends who had an older dog policy (dogs 8yrs and older)
Only basic cover and we would .only get a % of the claim paid out. In the end we didn’t claim for her illness (Spinal Cancer) as we were upset and didn’t want the hassle.
I think most insurances are a bit rubbish for older pets unless you paya massive premium buyer were only paying £13 per month for the basic policy