What you actually need to be looking for are the many threads on problem eating or finicky eating -- there are a few recent ones! Don't start changing around her food just to please her-- many puppies go through a phase of refusing food because you then fuss over them and try and cajole them to eat so they quickly learn that holding off eating gets more attention. They can be quite smart and manipulative about this! So just give her her food and do NOT make a big deal of this. Food n ground, she gets 10 minutes, ignore her the entire meal, after 10 minutes REGARDLESS of whether she has touched a single kibble, lift the food, no comments, don't even look at her, put it away. Ignore her for at least 5-10 minutes and continue normally with your activities. The idea is to remove ALL special attention from being associated with food, from the start thru to the end of the meal period. Do not giver her ANY food, ANY treats, until the next SCHEDULED meal then repeat the above. Within 2-3 days she should be eating normally. This is a behaviour and training issue, not a food issue. She can go a day or two without eating at all if she wants to be stubborn, quite safely, but most dogs get the idea by the third meal -- eat or the food vanishes. This kind of behaviour can turn into a serious feeding problem so don't let it accelerate.
Just out of interest, how many meals are you feeding her? At her age she should just be on two. If you are trying to give her a third she is probably just not interested any more and you should drop that meal. Some dogs even go to just one meal.
In general I like to feed a variety of foods anyway -- just kibble is pretty darn dull. But I would get her on to a regular feeding schedule BEFORE you start trying to add some new things for variety, or consider changing her food. Believe me the issue is not the food, it is simply that she has learned swiftly that there are benefits that come from holding out.
PS the best solution is competition -=- eg a second dog! :lol: Nothing focuses their minds more on getting that food down than the worry that a companion will eat it if they don't. When my Jaspar was a singleton puppy, he frequently played games with food -- in his case he wouldn't eat but would go sit at a distance and wait for a cat to investigate then he'd rush the cat. Then go back and wait for another cat to do the same. Once he realised he got 10 minutes and that was IT, and I switched him to a single daily meal to reduce the opportunity for games and made sure he was nice and hungry, he ate his entire meal in seconds, no more games.
PS I recommend switching to Burns anyway -- it's a great food.