This is probably buried in your feed enough you won't notice but I will reply anyhow. I actually missed the prelim fights but looked back at the highlights on the Dern fight.
Looks like typical transition from grappling to MMA growth. Those head down, flailing overhand rights are so typical of the BJJ fighters who have striking game to hone as you point out.

I like this about BJJ, you can still win MMA fights with limited striking. She has a great team that will polish and develop that.