Starting solids

So my baby is almost 5 months old and she was sleeping though the night since she was a couple weeks old. In the last couple weeks she started waking up at night and nursing. Now she’s waking up every 2 hours to nurse. She’s a big girl almost 17 pounds. So I’m wondering if I should start giving her oatmeal baby cereal before bed? Would that help her stay full longer so she could sleep through the night again? She hasn’t started any solids yet ( I was going to wait till 6 months pediatrician said it’s totallly up to me to started any time from 4 -6 months). She been exclusively breastfed so far. So what do you all think?