I have been approached by Guardian Inheritance in connection

We are not able to comment as to whether a company is good bad or indifferent unless it is an obvious scam. This company appears to be a member of the Society of Will Writers which is not a statutory regulatory organisation and therefore, if something goes wrong, you are faced with dealing with the company direct.
There are many companies like this who generally charge a fat fee for setting up these trusts and in some cases, the directors of the company are appointed as trustees. I think that's probably unsatisfactory. If the company goes bust you have no one to turn to and for that reason, if you are thinking of doing anything like this I would strongly suggest that you saw a solicitor to provide some continuity.
However, these trusts rarely do what you want them to do. The reason is quite simply that if you put your property into a trust and continue to live in it, it is called a gift with reservation which is a gift which is not really a gift at all. The only time it works is if you put the property into a trust and then don't live in it or keep any interest in it or you pay the full market rent to the trust beneficiaries. Ask them if the directors will personally guarantee that the property will be 100% safe from the payment of care fees. I think you will find that they are reluctant to do that! If in doubt, go and see a solicitor who can take detailed instructions and advise you in depth.
What you should do however if the property is in joint names with you and your daughter make sure that it is held as tenants in common and if it is not held as tenants in common, then sever the joint tenancy. That way, at least only your half of the house is at risk to pay for care fees. If your daughter is living in the property, the local authority cannot force a sale of the property and would only get a charge on your share of the house apart from £23,000 worth which is exempt.
Can I clarify anything for you?
Jo