S2 why would Beocca bring Thyra to the battle for London?

He could have left her at Cookham with Uthreds wife and I am sure Uthred would def be ok with it. Uthred even makes a comment that his wife is safe because he left her at home. Thyra has no connection to Alfred's daughter because, Thyra is a pagan and the queen hates pagans so it wasn't a protection thing. Only thought is Thyra would refuse to be anywhere other than with/near Beocca. Ultimately, it was very dumb decision by Beocca.