If your blender isn't designed to puree, it's a good idea to pre-chop fruits and vegetables so that the blender doesn't strain to break them down.
Make your own applesauce (or buy baby applesauce from the store), puree peaches or other fruits to mix with plain yogurt, or give small pieces of banana (grapes too for older babies).
You will discover that many fun fruit fillings are in season during the springtime, but are unavailable other times of the year, such as a blackberry puree, which is perfect in combination with a French vanilla cake.
Note - Although Italian Bellinis call for peach juice, there have been many variations so feel free to experiment with your favorite fruit juice or puree.
A key difference between Vitamix and other machines on the market is that Vitamix thoroughly blends every component of a juice or puree, whereas a juicer separates and discards rinds, pits, pulp, and other hard-to-digest substances.