I'll first tell Shanice that "It's okay to be shy when speaking up in front of others, if you mess up remember to stay calm and collective"

I'll first tell Shanice that "It's okay to be shy when speaking up in front of others, if you mess up remember to stay calm and collective".  I would try to give some encouragement before the meeting starts; "giving a good first impression is important, make sure you act professional in front of them and we'll understand if you are nervous the first time, it happens". Reminding her that everyone started the same way; is a good way of showing her that everyone had to start somewhere.

I'll start the appraisal by introducing everyone to myself and to the employee who is new to the meeting, I'll then resume with my ideas.  I'll then have stopping points in the meeting for everyone to give some ideas or comments (I'll give Shanice a chance to talk or even add a comment to other's comments/ ideas).

I'll try to show her what it's like to be in that type of environment, so next time there's a meeting; she'll hopefully be less shy and more confident.