She most certainly did serve - not as a mechanic, but as a driver - which required her to have basic mechanical skills as drivers were expected to perform running repairs where necessary. The article fairly accurately describes her training - it does not describe her subsequent service which did involve her driving military vehicles all over England. She was on active service from March until the end of July 1945, at which point, following the close of the war in Europe, she was released from active service along with thousands of other women who were among the first to be ‘demobbed’. It was only five months active service, but it was active service. The Royal Family do not claim active service unless they can do so on the same terms as any other members of the service.
She wasn’t driving a truck during the war, and she did not “serve” as a soldier, it was theater for photographs and public relations.
So you have the future Queen of England leaving Windsor Castle every morning and leaving her security people and the intense security of the Royal family’s residence, to go drive a truck around England during the daytime, and then drive back to the castle after the WWII work day so that she could sleep under high security at night.
All that so that she could serve in the last weeks of the war leaving all that daytime truck driving with the rank of Captain.
How many truck drivers enter military service, attend school, attain the rank of Captain and then are discharged, all in five months, all the time living under security, having little contact with normal soldiers, and spending her nights sleeping in the most protected residence of England in WWII for security reasons?
Any ideas why she waited until almost her 19th birthday to do all this, just as the war was ending and Germany was totally collapsing?