Will they send her a letter back refusing to issue her a visa since,
as an American citizen, she does not even need one?
No, they will either issue the visa or deny it. They will not send a letter saying she does not need one. American citizens are eligible to apply for and be issued visitor visas.
I also would not advise she flies to the UK if her visa is refused and attempt to gain entry as a visa-free national. Not advisable at all, read my personal experience. I am convinced if she does that she will be refused entry after her landing interview. She just started a job and appears desperate to enter the UK (from their viewpoint).
If you just submitted it yesterday, it has not been processed and I support @ Giorgio’s suggestion that she withdraw the visa application
Credit:stackoverflow.com‘
4 Mar, 2024
5 Mar, 2024
5 Mar, 2024