Oh, just pick something that you'd expect a child to be able to do, have, eat, drink or experience and it'll be that.
Whatever it was, it would be 'too good' for me, I was 'allergic to it', I'd look stupid and ruin it, it would 'just send you stupid', I'd only hurt myself or embarrass her, I didn't really want it/didn't need it/didn't deserve it or only stupid rich people had that sort of thing.
Start at being allowed to wash more than once a week (yes, wash, not a scrap of water was permitted to touch me outside Sunday evening), grow more than one size in shoe or clothes in a year or eat anything that wasn't the cheapest, lowest quality processed version and then move on to having friends, thinking I was special in any way, leaving the house after 4pm or at weekends/holiday, having a clean, safe environment or looking at her a bit funny.