Evening Richard, this article may offer you some help 'The Beverage Intake Questionnaire: Determining Initial Validity and Reliability' by Hedrick et al. It can be found at http://www.sciencedirect.com/science/article/pii/S0002822310005250

Ric,

I would simply call you but thought my answer might be of interest to others as well.  To my knowledge there is no validated questionnaire for measuring sugar sweetened beverage consumption with children.  Almost all the work that has been done on beverages has been done with adults (see the article mentioned by Green as well as Chambers E IV, B. McGuire, S. Godwin, M. McDowell and F. Vecchio. 2000. Quantifying Portion Sizes for Selected Snack Foods and Beverages in 24-hour Dietary Recalls. Nutr. Res. 20(3):315-326). 

The problem with the BEVi questionnaire is common in many Food Frequencies - there is no use of portion size estimation aids (PSEAs).  Of course with beverages PSEAs don't necessarily help either, although there is some data suggesting that appropriate selection of aids (even 2 dimensional ones pictured on the questionnaire) might help.  Note that the BEV1 questionnaire shows reliability of only about 50% and shows quite high deviation for some beverages.

One option if you are doing an intervention study is to provide a standard container for children to use over a period of time when they drink.  For example, in our research when participants used a 20oz soda bottle to drink from, they showed little deviation from reported vs actual consumption. 

Also the Beverage consumption questionnaire is probably too complicated for children.  It breaks things down into many categories that probably would serve to confuse children as much as help in understanding.

Another problem with the idea of trying to measure sugar sweetened beverages is that children may not understand what a sugar sweetened beverage is vs one sweetened with artificial sweeteners.  Even many adults confuse issues such as juice beverages (even 100% juice) as thinking they are not sugar sweetened when they are.  You will have to be very clear in your research, both scientifically, and with the children what constitutes a sugar sweetened beverage. 

Good luck!

dear Richard

my Thesis is about, The association dietary pattern and early menarche, I use a FFQ that is validate by Mashhad university it contains all of food such as beard, fruit, rice, sugar and etc. not only  sweetened beverages

if you can use this FFQ, I can translate it and send for you.

good luck.