Yep, on 'steady' she'll still heal using Embrace as usual, but won't cast any other spell. However, once you give her a manual command, she will revert back to guard stance and pretty much blow every cooldown she has. So be sure to put her back to Steady after making her use Whispering Dawn for example. Don't put her back to steady too soon either though, or you'll interrupt the Whispering Dawn command itself if she's still in the process of casting it. Makes sense, doesn't it? -_-

Yeah, did I mention the pet controls are horrendous? lol