It’s an almost universally held belief among YECs that just because scientists don’t know everything about the history of the universe, that somehow means that they don’t know anything about the history of the universe, and that everything under the banner of “historical science” is therefore fair game for denial. It’s a fallacy that crops up so often in discussions with YECs that whenever they bring up any unknown or uncertainty in mainstream science, there’s a tendency to automatically assume that this is another example of it.
There is the possibility that Valerie is not trying to make that point, of course, and that we’re jumping to that conclusion erroneously. But if that’s the case, since she identifies as a YEC, she needs to make that clear because it would make her very much the exception rather than the rule.