Personally, I don't like to give any added sugar other than the occasional pinch when cooking something (like I add a pinch of sugar to my tomato sauce, for instance, otherwise it tastes like crap). Generally, I think they say no added sugar to about a year. Once probably isn't going to hurt, but there are plenty of other things if you don't feel comfortable with it. I think it used to be the practice in older generations to feed babies up on sweet foods and puddings to help them put on weight (back when our diets weren't as great or food wasn't as plentiful), so that's probably where she's getting it from. Things like nut butters, hummus, banana or other fruit puree/mash, or even yogurt work well too (or just plain butter), if you would rather she not use jam though.