I gave her a drop of strong sugar syrup and she perked up very quickly. While she was drinking I had the opportunity to take a few photos. Close up the bee's proboscis is amazing. It consists of a stiffer outer split tube, formed by the mandibles, and a longer, flexible, extendable inner tongue which is hairy at the end and is used to lap up the sugar. Normally of course the tongue is poked down the inside of a flower. Bumblebees have longer tongues than honey bees and can drink nectar from deeper flowers.
After a few minutes this bee flew off. Let's hope she establishes a successful nest and learns to stay out of the greenhouse.