Hi Camicia and welcome.
Like some other posters have pointed out . . . possibly your daughter has emotional reasons for wanting to press on toward becoming JW. You mentioned depression/ anxiety as something she struggles with. If this is the case . . . reasoning over doctrines etc will have limited value IMO. The attraction will simply be the comfort she feels . . . from the absolutes regarding the future . . . and the willingness of others to show interest in her without her having to initiate relationships.
With even low-level mental illness problems surfacing at her age . . . joining this cult will be a very dangerous step . . . it will seriously damage her without doubt. I feel you would be helpful to her if you did your best to be an alternative source of comfort . . . to be kind and considerate and caring to the greatest degree . . . spending time with her doing the non-religious things which she has shown interest in before. Basically, tightening your mother/daughter bond. Respect her right to make her own decisions . . . but do suggest she do research and think carefully about such a major decision.
If she has not yet been out in service . . . then you have a few months at the very least. Door to door work can be a challenge for someone like you've described your daughter to be.
It is a good idea to post here often when you're tackling a problem such as this . . . there are lot's of experienced wise heads here and many will follow your progress. So do keep us posted on any developments.
All the very best.