lol...I feel your daughters pain here. I'm not much of a pill guy myself, but you gotta do what you gotta do. I see my grandfather take down like 6-7 pills at a time and I can't believe it.
The liquid vitamin idea may be a good way to go, just make sure you're getting a quality source.
You may also want to look into going to A,B,C,D, and E route. Plus maybe throwing in some other "support" vitamins or minerals. In my experience the individual pills are not as big as the "multi" pills, but you obviously have to take more.
Also, the texture of the pill may have alot to do with it. With ON Opti-Men multi-vitamin, although not huge (but very grainy), can be a pain in the arse for me sometimes, while a capsule (such as ADAM) gives me no problems whatsoever. I find that capsules, gel capsules, and enterically coated pills are MUCH easier to get down. Food for thought, good luck!