8 month old won't drink. *UPDATE* UPDATE2

My 8 month old DD won't drink juice, I was just wondering if any one had some tips, I have tried putting it in her bubba, sippy cup, etc. Nothing seems to be working. We started putting it in a sippy cup first, tried a few different brands, she will chew on it but wont drink from it. So my mother suggested just giving her juice in a bubba, and I tried that too but she doesn't want it. Any tips, or is it normal for babies this age to not really drink anything besides formula? 

UPDATE: Her pediatrician recommended juice&water< she won't drink either. She only has MAYBE 4 bottles a day, her pediatrician didnt want to risk her getting dehydrated. I just wanted to know if anyone had any tips about getting her to drink juice/water. I just want to go by the pediatrician, she's really great and I believe her when she says that she should be having some juice/water. Thank you gals for your tips, but I just think I should listen to the pediatrican in this case, so if anyone has any tips of how to get her to drink juice/water that would be helpful, I understand that she doesnt need it yet, but this is on her pediatricians remondation.

UPDATE2:

 I wasnt asking if people thought I SHOULD be giving her juice/water, I was asking of tips on HOW to give her juice/water. My pediatrican has recomended this to help with her constipation issues, I did not add that in the OP because I was not asking if I should I was asking for tips on how. If your not going to answer the question, why comment on the post??

thank you to all the moms that actually helped me with advice! :)