The Cleaner, the Cat and the Space Station

There's an alien space station orbiting the Earth, secretly protecting us from invasion. And it's recruiting humans like you to train as fighter pilots.
A heart-warming first contact adventure featuring an unlikely heroine, aliens, astronauts, a shape-shifting Welsh dragon, cyborgs, spies, space pirates - and trees in space!
Since leaving Ethiopia, Hanna Abebe has survived in London by working illegally as a cleaner. But her life unravels after a sexual assault; living rough, she loses the resulting pregnancy and very nearly her life. Salvation arrives and Hanna's rescuers welcome her into an unusual new family: a school for recruits to the Shantivira, the secret space station which protects the Earth. Then Hanna uncovers a traitor in their midst . . .
Lucy Cooper is horse riding on Dartmoor when a mysterious shape-shifter appears out of the mist and offers her a place on the Shantivira's fighter pilot training programme. Unnerved, Lucy's instinct is to refuse. But an organisation claiming the Shantivira's motives are more sinister approaches her and persuades her to become their spy . . .
Joe Llewellyn is bored. Being the captain of the Shantivira isn't the challenge he'd hoped. Plus, he'd like to inform the Earth about aliens, but his boss won't permit it. Then a stray asteroid hits the International Space Station and Joe is forced to let the cat out of the bag . . .
This uplifting blend of fantasy and science fiction is a must-read for fans of Becky Chambers, Ursula Le Guin, Ben Aaronovitch, Douglas Adams and Doctor Who.