Hiya - lovely Xmas present, not!
There are NOT Nil carbs in grapes, even if you only have 1. and 10g carb was always 5, but maybe more of the seedless ones which weren't about all that much in 1972 when I was told that! Same with carrots. But bearing in mind the modern approach is to not inject extra fast-acting for snacks less than 10g carb, then that is probably what she meant.
But I thought to myself in 1972, who the hell can stop at 5? and I have literally NEVER bought or eaten a single grape since then*. Patti - a member here and elsewhere - describes them as 'individual little bags of sugar' - and that's about right IMHO!
* except thoroughly squashed and fermented of course! - even subsequently distilled and bottled with a label eg Courvoisier VSOP etc ......
I tell you what else is good - the Collins 'Gem' CALORIE counter. Gives cals, carbs, protein, fat and fibre for 1,000's of foodstuffs, all expressed per 100g weight, or 100ml if it's liquid. Very very useful for cooking purposes. And various supermarket own brand stuff, although most UK packing materials have the carb count on the label. (They do a carb counter book too but it's too vague - eg A third of a baguette = whatever - but how big was the original baguette? - doesn't tell you ....)
Good luck !