Yeah, filling her up earlier in the day when she's more amenable might be a good idea. What time do you have dinner? Maybe she's too tired to eat properly? My DS is younger, but we find we have to feed him early or he just can't eat.
We do offer him a supper plate before bed to fill the gaps. It's hard to find that balance between getting them to eat properly and getting them fed so they'll (hopefully) sleep.