Baby wakes up at night to lick her hand

My 4mo has been waking up in the middle of the night to lick her hand, or even her sleeves, if her hands are covered by her sleeves. She does that with her eyes closed and only stops if we swaddle her tighter and keep her hands out of her reach. However she is getting stronger and also starting to flip, so it seems like the swaddle won’t be a solution in the long run. Any advice on how to get her to sleep better? #advicepls #firsttimemom