Before taking food to cook for herself?
Genuine AIBU as her attitude towards me stinks in general & I'm not sure if I'm reacting to that more so.
She's almost 19, at college & we are more than happy to feed her, but I just think she needs to ask before helping herself to items I might already have ear marked for meals.
Just watched her pick up a chunk of ginger root, to which I asked her if she could use the dry spice, as I bought that for a reason... cue angry hissy fit, asking how much she needed as maybe I could spare a little, had her scream hysterically & throw the ginger across the kitchen & a huge passive aggressive outburst about how she's been spoken to like dirt for feeding herself & made to feel unwelcome... erm nope, that didn't just happen 
Surely it's just common sense & good manners to ask. She always used to, but suddenly feels she doesn't need too 
Thank you