It is always wise to be cautious with babies, especially with other celiac sufferers in the family. Of course you do have the advantage in knowing what is gluten free and not having to learn it whilst having a young baby.
I used to toast gluten free bread fingers for my little ones and spread with a little margarine and marmite. You can buy baby rice cakes now, some flavoured, that my grandsons loved to suck on.
Fresh fruits, such as a piece of banana, or melon are good to "gum", but you might want to keep baby confined in a highchair if you don't like mess!
If your baby has no lactose issues you could offer her a small chunk of soft cheese. And if you are not vegetarian how about a piece of cooked chicken?
Hope these ideas help.