It’s only radiant resistance, right? Being a light fairy already grants that. You can take away the bonus cantrips if you like; I can grab sacred flame as a cantrip with my sorcerer subclass all the same, and the light cantrip was already granted as a bonus with my racial choice.

I was really only interested in the bonus damage for radiant and fire spells. It will allow her to make some otherwise uninteresting spells her bread and butter. (Notice she doesn’t even have eldritch blast - I would rather use sacred flame and fire bolt).