Waking child

My 3.5 year old daughter has been waking up every night for over a month now. She says she is up because of shadows, noise or cold. She what been an awesome sleeper with no problems and then all of a sudden a change in her sleep. There has been no change in her routine or anything else either.
She has a night light (as I need it for seeing due to my eyesight) and has requested another one for her room, which we have done, however she still wakes between 12-4am.
I always reassure her that nothing is outside or in the cupboards etc
Is this a common thing for others as well? What have you done to help the little ones settle?