Well - seeing as it's my birthday, I think I'll get away with it
grannyactivist did a Product Review on it - it's Molton Brown's Radiant Lili-pili hairwash. Both it and the conditioner are £18, but the assistant said that the shampoo would last about 6 months and the conditioner would last even longer as I'd only need to use that after ever second wash at most. Gorgeous perfume! We are worth it, aren't we, crimson?! 
Thank you Anagram! And I do know what you mean about being exhausted after having the young ones for what you see as only a short time. My husband is nearly 73 and I find it's more trouble trying to keep him happy when we've got young visitors, than it is to have the young ones visit! 