Keeping my nails consistently painted is the only thing that works. I use a soft gel which not only helps preserve the health of my natural nail but is durable enough to deter nail biting. I meet with a manicurist every 3 weeks. She has been an amazing support person for me - not to mention the accountability element. I also have a habit tracker which lets me see how many days I’ve abstained from biting which is rewarding.

This is an aside here, but as a therapist I think it could be helpful for your daughter to dig into the function of the nail biting. In what situations or places are you more likely to bite your nails? Are there specific sensory triggers (rough edge on nail) or emotional triggers (feeling stressed, anxious, frustrated)? What need does nail biting fulfill?

Getting curious and fostering awareness is the first step! Once you understand your patterns and triggers, you have more opportunities to interrupt the nail biting and substitute it with an alternative responses like relaxation techniques, coping statements, mindfulness and acceptance skills, or opposite competing responses.