Thumb suck at 3 mos old

Totally normal, mama! At 3 months, thumb sucking is actually a reflex and a way for babies to self-soothe, so don't worry, it's not something you did wrong haha. The thing is, it usually becomes a habit by around 6-12 months, and most babies naturally stop it by age 2-4 years, but if it continues beyond that, it might affect her teeth alignment later on, though honestly, we cross that bridge when we get there, diba? For now, just let her comfort herself; she'll outgrow it when she's ready, and you're doing great for being aware!