Uy, para sa ubo ng baby, kailangan talaga makita ng doctor muna, hindi dapat mag-self-medicate ang 3-month-old, even with common meds. Please bring her to the clinic or pedia asap para malaman kung ano talaga ang sanhi at ano ang safe na gagamitin. A few of my mum friends had the same worry, at laging sinabi ng doctor nila na dapat prescribed lang ang lahat for babies na ganyan kaliit. Take care of your little one!