My lil one has been on Euk since I got her and it is now time to purchase a new bag of food...(I've had her 4 mths now) I am really confused as I have gotten samples of Natures Balance, Canidae, and Blue. Of course she enjoys them all....Can anyone recommend which one would be the best

Plus she has changed her eating habits from eating 1/3 cup first thing in the morning, and then again 1/3 cup @ 6:00 pm. She now doesn't want to eat at all during the day/evening and instead waits till during the hrs of 12:00-3:00 am....I know she has been teething and may also be getting close to her first heat....She is 7mths old...Any shed of light would help alot.....