In reply to Chloe:
What sort of boots are you needing? Winter? Lightweight?
Could you use trail shoes? I only wear boots if I need crampons. Trail shoes are easier to get in small sizes, give better grip on more surfaces, better precision of footwork and strengthen your ankles so help to protect against injury.
My friend who has tiny feet uses Salomon trail running shoes, not sure quite what size she is but very small.
If you need boots to wear crampons, La Sportiva do boots down to size 36.