What a nightmare, so sorry OP. I'm an ex-LL and this is the thing we all dread. Thank goodness nobody was hurt.
Obviously, the insurance company will be your first port of call and you should talk to them about how it works on a practical level:
You'll need to schedule quotes and inspections from gas engineers, electrical engineers, kitchen fitters etc. Any safety certificates you have presently will clearly be voided so after the repair work is done, you'll need to reschedule all the inspections.
As far as providing her with somewhere else to live - I'm not sure that you are necessarily obliged to do that, but of course, you can't charge rent if the property is uninhabitable. It depends on what it says in the contract. I would honestly not want her back, given the level of utter stupidity she has demonstrated and the amount of hassle she has caused. If this isn't clear in the contract, obtain legal advice, which you may be covered for under your landlord insurance policy.
If you are not covered for legal advice, you could consider contacting a specialist firm - Landlord Action are pretty good, or you could contact the various Landlord's associations for a recommendation.
To be blunt, issuing an eviction notice ASAP to start the clock ticking may be your best option, with it to take effect before the property can be rendered safe and habitable again. That way you won't have the battle of physically getting her out.
As the property will now be unsafe to live in, you can't allow her to keep living there while the work is ongoing even if she wants to be there - you'd be in breach of many safety regulations.