Adult workers should receive either:
an uninterrupted 24 hours clear of work each week ; or
an uninterrupted 48 hours clear each fortnight.
(While there are exemptions from the Working Time Regulations for staff working in '24 hour care' environments, it's unlikely that they could be used to keep anyone working for 6 weeks at a time):
http://www.direct.gov...ndTimeOff/DG_10029451
Unless your wife is genuinely self-employed,her employer should meet all necessary expenditure incurred during the course of her work (such as the costs of using her own vehicle).
Your wife needs to ensure that her car is insured for business use (and her employer should meet any additional costs incurred through changing the policy).
The ACAS helpline is an excellent source of advice:
http://www.acas.org.u...x.aspx?articleid=2042
Chris