She doesn’t need anything in her account. Your savings is what the officer will want to see. However the officer may want to see her bank account statement to back up any claims she makes in the application about income from home country etc.
Good luck with it. My girlfriend spent summer with me in uk and returns tomorrow
someone on a group mentioned the Q meant it was a self administered test. They said it’s ok for Thailand but emirates questioned it for transit at Dubai however after discussions they were allowed to travel.