Betty is a five-year-old female koala with brown and tan fur, black eyes, and a dark brown nose. Her usual outfit is an orange dress, yellow socks, and brown to reddish-brown shoes. Alternative attire includes swimwear featuring an orange strapless bra and matching briefs, often layered with a ballet tutu the same color as her dress, or light yellowish briefs paired with a sleeveless tank top.

Her personality blends kindness with vanity. She dates Roobear, though their relationship faces recurring misunderstandings. Her friends include Roobear, Floppy, Laura, Pamie, Nick, Mimi, Mingle, and Kiwi. Her interactions with the kangaroo brothers—Walter, Colt, and Horsey—fluctuate between friendly and adversarial, making them frenemies. She harbors a specific fear of characters in disguise.

In the series, her actions demonstrate consistent traits. Entering competitions like the flower queen contest creates tension for Roobear, caught between supporting her or his sister Laura. Others harbor crushes on her, particularly the shy Walter Kangaroo who struggles to confess his feelings. While her vanity sometimes leads her to prioritize appearances, she consistently shows concern for others' well-being. Her characterization remains consistent across the series, with parents mentioned but not detailed.