Gift it to your child since you felt she is longing for it. My humble suggestion is, it entirely depends upon you as to what you want your child not to see on internet.

I appreciate that you have gifted her books which she feels can be downloaded as e-book easily to which I agree with her on this, at the same time, there is this 'Firewall' settings which prevents acces certain web contents & can be easily done by any IT expert so just set it up on the Ipad before you handover to her, therefore, you do not have to worry if she is taking it to her room or if spending long hours with it, just relax she is not viewing any web content which is inappropriate for her age, also not causing any harm for her studies.