It is against the ToS for a client to ask for a free test or any work before a job has been officially awarded. It is clearly not advisable for a freelancer to do so, particularly a newcomer, but there is nothing in black and white prohibiting it.
The OP should report this client, who is obviously circumventing. However, as Jennifer pointed out, it is a matter of common sense to nix this sort of job.
Edited to add: The OP has also stated publicly that she will do a test - a very bad idea as it is an open invitation to all scammers or clients who disintermediate.