You can move it if you want to, but you should try and make sure you have as few walls as possible between the router and where you normally use the wireless signal.
Why not put it in the study itself? If you don't have a phone point in there, then it sounds like the bedroom next door is the best option.
If on the other other hand you meant should you move it because of the fact your dd sleeps there, the answer is no. the word 'should' implies you would have a valid reason for that course of action, and there isn't one.