1) Yeah she can TRY to do it anywhere and you can have the sheep cherubs/imps immediately dogpile her for comedic effect. Feel free to do as you please with that gag!
2) For being able to actually cast it, as long as it's not in a populated area and for rule of cool/funny, that's fine! You can make up plenty of disposable areas to use it, like out in the middle of the ocean or a disney-esque forest in heaven away from the main city! The cherubs/imps will still try to tackle her afterwards but can just be a bit too late and be crabby they have to fix/repair the area.
Re: PHENOMENAL COSMIC POWER
2) For being able to actually cast it, as long as it's not in a populated area and for rule of cool/funny, that's fine! You can make up plenty of disposable areas to use it, like out in the middle of the ocean or a disney-esque forest in heaven away from the main city! The cherubs/imps will still try to tackle her afterwards but can just be a bit too late and be crabby they have to fix/repair the area.