Adding to my colleague's response, set a bed time routine. Avoid your child using any electronic gadgets 2 hrs prior to sleep. Reading stories @ bed time is a good habit. Give lots of love and reassurance to alleviate any insecurities she may have. Help her to build a positive self image. All the best.

In most of cases Teeth grinding is due to psychological factors rather than physical illness. As she will grow it will stop. Just make sure that there is no emotional issue, family issue which can sometimes make children feel insecure. Again suckling of fingers is also emotional and best way to reduce it is to talk, distract and engage with her when she is doing it and avoid instances when she is bored, alone. This will stop as she grows older.