After Heinz was done attacking, they gathered together and Axel gave some input to him on how he could improve, Vyra also added some comments in between, Lumina simply kept quite since she did not know much about physical combat.
Then Vyra took her turn, who without her arrow and bows she was also quite lacking in direct physical combat. Then came Lumina's turn, considering how paranoid Lucien was about her it was surprising he didn't teach her combat. Oh well, he didn't care that much about it honestly.
Axel simply helped her, advising on the most basic things like stances, sword grip etc, since she seems to be a total beginner. Letting her swing the swords wouldn't be helpful since she did not even have the basics covered.