Rusks biscuits, and heinz baby biscuits, Ella's kitchen melty sticks... are all lovely and good choices. My LO loves them, maybe worth checking them out? Only thing is, I don't know if they'll be okay with your LO's allergy... double check that first xx
I don't often give a snack but I do use the waffers and the puffs you can get if our meals don't match hers so she has something to chew on when toys aren't enough to keep her occupied while I eat. Fruit is always a good snack. A few mashed up bits of fruits always good