Start with any base class and add this on as a modifier. It costs you 1000XP more to reach 2nd level, modifying how long it takes you to level all the way until you stop gaining hit dice (+2000 to reach 3rd, +4000 to reach 4th, etc). Explicitly stole this gag from Josie X.
You can be a fighter trying to make ends meet, a cleric selling kitschy Pelor memorabilia, a regular old hobbit waitress, etc. Shopgirls can be boys too and you can call that whatever you want. I'd probably call them Shopgirls still but if that's sensitive for you then use whatever, or just call it Shopkeep.
Shopgirls have four abilities:
Shopgirls count as one size larger for determining encumbrance, lifting, forcing doors, etc. If there are attack or AC penalties for being over-encumbered in your game they do not suffer those.
Shopgirls can clean a non-supernatural mess in a room in the span of an exploration round. Afterwards they must rest or be exhausted until their next meal, where they will consume 3X normal. A successful save against magic also allows them to clean supernatural messes (within reason; green slime still eats their mops) but a failure means they make it twice as bad in the process.
GOOD DAY, SIR!
Once per day a Shopgirl can raise her voice and put her foot down, forcing a morale check from creatures with fewer HD than she or a second initial reaction check from creatures with greater HD than she.
Have You Seen The New BT-16?
You choose what kind of shop you work for. Whenever you encounter the kind of thing sold in that shop you can identify its type and provenance, and tell if there is something remarkable about it. "Those are Chiluhixan shoes. They look magic!" "That's a Kingsbury loaf. OH, that's a bad bake Mary, it smells like poison!" "I'd recognize a Henderson quill anywhere. Henderson quills, because geese don't grow on trees. Anyway, this model hasn't seen circulation for a hundred years..."
Shopgirls require some manner of certificate, promotion, honorific, official recognition, or bonus perk in order to level. These cannot be granted by a god or king but someone much more important: a Shopgirl's boss. Means even if you bust your ass in the dungeon you've still got to be punctual and impress people back at the shop.