The Twitter account 'Crimes of Britain' posted a picture suggesting that they did, but pictures can be deceiving, and CoB isn't exactly a neutral source, so I wonder if there's any truth to their claim.
The suggestion by the account is without evidence with the exception of the image posted, which is a real stretch when it comes to depicting a soldier using a child as a human shield. The twitter account has a very strong bias against the UK and this should be considered when you want to consider whether a professional army in a highly visible and documented conflict would use children to shield them from gunfire.