Wow, the pediatrician told you to just give her water until she eats what you want her to eat? I would get another pediatrician. For the most part, babies eat what they need to eat. There is almost NEVER any reason to stress out over what a baby eats, as long as you provide the baby with the right kinds of food (proteins, vegetables, fruits, starches) and don't get the child hooked on junk food. The baby will eat more of one kind of food than the other at different times, depending on what his or her body needs at that time.
One huge cause of babies and young children giving problems over eating is parents being stressed out and worried over their children's eating habits. If you are relaxed and don't place a lot of importance on your child eating everything you set in front of her, she is more likely to eat peacefully. But if the child picks up on your stress and your worries, she will become nervous, and when a child is nervous, she is less likely to eat. Also, when a child senses that what she eats and how she eats produces a reaction in Mom and Dad, she sees mealtimes as a huge power struggle, and so there will be battles because children like to feel powerful.
I think what you need to do is stop the power struggle. Do not react to what your child eats, as long as it's good food. Do not offer junk food just to get the child to eat something. Kids go through growth spurts where they're eating everything in sight, and then their bodies rest for a while, and they don't need as much food. As long as the child is healthy, she will manage to eat what she needs from the things you offer her. She will also manage to drink enough when she's thirsty, so you don't need to stress out about that, either.
You can also try combining foods if she's still on strained or mashed-up foods. If she likes mashed potatoes, for instance, you can try stirring in a little bit of strained vegetables so that she will not taste the stuff she might not eat by itself. Hamburgers can have all kinds of vegetables hidden in them, if you cook the veggies and put them in the blender first, then mix that up with the hamburger and make hamburgers or meatloaf.
There are all kinds of tricks to getting kids to eat good things, but the first thing I think you need to do is to get rid of the worries. And that weird pediatrician. Naturally, it works better if you try to feed her when she's hungry, but making her extra hungry by keeping food away from her altogether for a few hours -- that's just cruel.
Well, I hope this is helpful.
