If I may, no it's not crystal clear. It is to you because that is what you want it to be. Another person who reads it may not think Valkyrie, only security consultant. By your own argument, we are not told that it is a Valkyrie job, just a security consultant job. You are making the assumption that Valkyrie and security consultant are one job when it is not specifically stated that it is one. It could be that all the Valkyries hold that position, but not all security consultant for Odin are Valkyries. That is an answer only Jim can give.
The conversation happens after Murphy fights a den of supernatural creatures. It's not happening after Murphy demonstrates that she knows how to protect a banker's assets from being stolen, or stopping industrial espionage.
The thing that Murphy has demonstrated is her ability and willingness to fight monsters, and that is the thing that makes Gard offer her the job.
The thing that gets Gard's attention is the knowledge and skill that Gard uses for her job in fighting supernatural monsters.
There's nothing in the context of that conversation that says, "I want to give you a totally mundane job literally acting as a security consultant."
Look, this isn't complicated. Authors, like Jim, use repeated phrases to directly link ideas.
He links Gard to the phrase "security consultant," and through her actions and interactions with the cast, it becomes clear that that's code for "Valkyrie," especially after we know that her boss is Odin. Through Gard's words and actions we know that, among other things, Valkyries are kickass warrior women who fight supernatural creatures.
So when Gard -- the Valkyrie -- comes to Murphy after Murphy has just done one of the things that Valkyries do, and offers her the same job that Gard -- the Valkyrie -- does, using the same title she used to refer to herself, that means that Gard is asking her to become a Valkyrie.