My friend milbroom pointed out HB seems uncomfortable eating in front of others other than Amelia so here you go! She never seems to eat much so just a oneshot which you can interpert how you wish!
Grapes For Tea
Mildred opened the staffroom door and walked inside without knocking, hearing a gasp as she did so. She had a few seconds to see HB chewing something before the potions teacher was suddenly by her side.
"What in the world do you think you are doing girl!?" Constance asked, her throat burning slightly, the way it did when you forced yourself to swallow to fast.
"I..I am sorry Miss Hardbroom...as the party is going on I didn't think anyone would be in here" Mildred replied mentally slapping herself for not knocking despite that.
"The party is hardly a reason for your lack of manners" Constance shouted. Mildred looked behind her, seeing the table behind her was set up with a bunch of grapes on a plate and nothing else.
"MILDRED HUBBLE" HB now yelled as the girl daydreamed. Mildred blinked and came back to reality.
"Well? You might as well tell me what it is you wanted now you are here" Constance told her. Mildred nodded as she remembered the reason.
"Algernon said to leave some of the crumpets in the staffroom for the staff to have later" Mildred explained, showing her teacher the plate.
Mildred suddenly jumped as she sensed someone appear behind her and she came face to face with the headmistress.
"What is going on? What is it you wanted Mildred dear?" Amelia asked her, walking to stand in front of her.
"I am sorry Miss Cackle, Algernon told me to leave these crumpets here, for the staff later" Mildred explained again.
Amelia nodded and took the plate before speaking "Right thank you Mildred, run along now, you don't want to miss the party" Amelia told her.
"Aren't you coming Miss?" Mildred asked her.
"No, I have some things I need to do, we will talk later Mildred" Amelia said shortly, telling Mildred the conversation was over.
Mildred stood there a few seconds more before leaving and closing the door. Outside the staffroom, Mildred couldn't help think how strange Miss Cackle had being. True, she had been in the staffroom, not exactly a place she was welcomed but Amelia had seemed desperate to get rid of her. Mildred thought she might still be a bit mad about the fighting with Ethel, so tried not to think to much into it.
Inside the staffroom, Amelia led Constance back to the table and spoke.
"Don't let her distract you from the task at hand Constance" she told her.
"What if she realised what we were doing?" Constance said
"I don't see how she would, come on eat up" Amelia encouraged.
Constance nodded and sighed as she picked up a grape of the plate.
"Return to the party if you wish" Constance suggested.
"I can't, I promised to help you, you have plenty of time to eat, the party won't be over for a while" Amelia told her, falling into the seat next to her as her friend ate the grapes slowly, feeling completely uncomfortable eating at a party.
"Thanks Amelia" Constance replied with a grateful smile.