Interesting character design! I'm not sure you've captured bubbly or stoner girl with the current dress she's got on. The white sun dress and blue sash makes her seem nice and wholesome. The type of monster I'd like to introduce to my mom.
I feel like a stoner girl would be more casual in what she would wear. Jeans and band t shirt, maybe a beanie or hat, shorts, boys windbreaker jacket, black stockings, etc. A bubbly girl would wear something with like...rainbow stockings, contrasting colors or garmets(white shirt, blue skirt, tie), red skirt, red polka dot shirt, layered clothing, etc, etc. Just my opinion. Keep it up!