Never had a problem with a child's meal after the crew confirm my 44yr old partner did indeed order it.
Outbound from London to the USA expect chicken nuggets (goujons) mash and peas, usually a plate of celery and carrots and fruit for desert, sometimes there is an abundance of grapes but not so much on the last flight and often a certain repetition between meals which could be an issue if disliked.
The second meal service usually has simpler sandwiches such as ham and cheese. and both meals have an abundance of other packaged items such as chocolate bars, yogurts, raisins, caprisun and or ribena.
Return from the US can be a bit more hit or miss and mac n cheese can make an appearance, but often its a variation of chicken goujons, more likely to see carrots and celery and apple sauce, sadly the cereal and little carton of milk has been enhanced away, that was always useful for the cup of tea once home with an empty fridge.
Rarely have a problem getting a fresh roll, pastry or bacon roll from the baskets as they pass through or an adult desert, often a whole adult meal is also offered or comments of how nice the kids meal looks