Reminder...

Here's my suggestion:

A young woman works in a large company, the daughter of the boss.  She is in charge of birthdays and events- a cushy job that is seen as a product of nepotism by the staff.  She puts her all into her events, and does many- always researching new "Days" to celebrate, and she seems to have a limitless budget.  Most just come by to grab whatever snacks and swag she's put together- ignoring her extensive presentations on each "holiday."  She discovers "Inflation Day," and researches it extensively.  Seems its origins go way back to a people who practiced inflation and were the one's who actually discovered Helium.  Their practices were lost over time, though some still have the ability in there genes.  She happens to have an ancestral link on her mother's side. 

On the day, she shows up wearing an oversized blouse and voluminous skirt.  Along with snacks and assorted inflatable items, she's brought countless helium tanks.  The disgruntled staff have no idea what to make of her latest presentation.  She begins by giving a history lesson while inflating some toys.  But as she begins to talk about her lineage and then, hose in mouth, begins to inflate herself, this pushes her co-workers over the line.  They assume she's wearing some rediculous inflatable suit, and they finally all let her know what they think of her.  Their mocking and laughter brings tears, but she also finds an odd strength in her swelling body.  "So, you all think I'm some big joke?  Wanna see something really funny?"