What does she want travel insurance for?
She doesn’t need health insurance in the UK as it’s covered by NHS.
If she has personal possession cover on household insurance she may not need cover for baggage.
If she wants cover for cancellation i.e. she might be in hospital or dead before the trip, then that is going to be expensive as she’s high risk and if it’s close to the cost of the holiday itself then clearly it’s not worth it.
So I would be trying to find out what she wants it for.
Anything that’s high risk is going to be expensive.