Wanda hesitated, but not because she had any doubts about what she was going to do -- she'd already considered the vampires equal dangerous equation, and set up her ship to return home on autopilot if anything happened to her, so she wasn't risking anything but herself.
But the mention of hypnotic powers gave her a momentary pause, and she was a little off balance when Buffy stated her intention to go on alone, as if Wanda might stop the moment it looked dangerous.
And she remembered someone else going off -- someone she'd sent off, though that had been in the heat of battle, two things that needed doing --
The memories that she lifted from Clint Barton's mind were too fresh. Wanda shuddered. "No!" she exclaimed. "You must not go alone."
She took a deep breath and pushed it all down, hard. Now was not the time to make Buffy doubt her by being overly emotional. "I know what bad is like," she said, carefully. "I will have your back."