I was going to suggest a jelly too - you can make a gel from diluted fruit juice and a little gelatine.
What about english muffins or crumpits? Cruskits and milk arrowroot biccies?
With the drink thing, maybe just keep offering the cup - even if its just a play-thing at first (that's all it is most of the time for Natty) at least they get used to it and know there's liquid in it for when they get thirsty? (Sorry - my DD is much littler than your little one, so I've not got any first-hand experience for you...)