There’s a few lady drivers on 7.5 Ton, Class 2 and Class 1 at Royal Mail.
All work is on yorks so you’re pushing or pulling a max weight of 250Kg each - Most weigh nowhere near that.
Really hard to get into Royal Mail but each Mail Centre/VOC have agency drivers, usually via Manpower. The work seems to have dried up for now on agency though - It should pick up around March time with a bit of luck