As documented in the linked document:
it excludes “those not renting the property as their main home”, so as long as she can document an existing main home elsewhere, she should be fine whatever the case (and even more so for a short let).
EU/EEA nationals have indefinite leave to remain, so can rent as long as they want by just showing their passport or ID card
for others, they are entitled to rent for the duration of their leave to remain. Note that as long as they currently have leave to remain, the landlord is “excused” for a whole year, so a 6 month let would not be an issue as long as she has a valid visa at the start.
Of course, many landlords may just choose to err on the side of caution and not try to understand any of it, and just rent to British nationals (and possibly EU/EEA nationals). Probably depends a lot on the cost of the rent, the type of let (short term vs long term), the usual “target” of the landlord, whether this goes through an agency, etc.
As I UK landlord, I would not to choose to rent a flat to someone that was only planning to stay in the UK for 6 months. There are a few issues.
So firstly I would need a “home owning guarantor” for her, that owns a UK home, has a good UK job and agrees to pay me any money she owes me. Then I would need her to offer 25% more rent that was I am advertised the property for.
But…
Short term holiday lets are outside of the “Right to Rent” regulations and their owners are setup for letting out short term, hence they charge over double what a landlord does.
Credit:stackoverflow.com‘