For that suggestion -- the girl go wait while the man goes to play hero, the Doctor gets a fairly dirty look. It's something akin to anything-you-can-do.

"Doctor, if you can forgive my earlier reaction," underneath the tone of confidence, is a warning not to ask, "I think it would be wiser if we do not separate."

Morgana has a perfectly logical reason for this, "In case assistance is needed."

Not that things ever go horrifically wrong around the Doctor, like almost dying not too long ago.

And because she's been wishing for it, "Next time, I will not take your advice and bring my dagger."

Wait, did she just imply the possibility of a next time?