Sorry, I should also have mentioned a way forward that may be more suitable than the lodger arrangement. Your daughter and her partner could enter in to a co-habitation agreement. This would set out the details of his living at the property, such as:-
1. The length of time it will cover
2. How you will treat the property owned by your daughter
3. Whether your daughter's partner is to acquire any interest in the property
4. How any property acquired in the period of cohabitation will be shared equally or proportonally
5. The effect of the co-habitation ceasing
6. Whether they intend for the agreement to be legally binding.
You could speak to a local solicitor to get a draft drawn up, both your daughter and her partner will need to take independant legal advice prior to entering in to this agreement.
This is probably more suitable than a lodger agreement.
I hope this helps, please do not click accept again.