Aw ang hirap nyan, mama! A few of us with toddlers in glasses had the same issue, the heaviness really does throw off their balance, kaya nag-slip constantly. I'd suggest going back to your optometrist and specifically asking about lighter frames (may plastic ones na super light talaga) or even adjustable straps/temples na mas secure, kasi parang need talaga ng extra grip sa 2yos. But honestly, I think best to have the eye doctor check if yung prescription itself needs adjustment or if there's a better lens option na lighter pa, kasi sometimes the grade demands thicker lenses pero may alternatives. Patience lang with your lo, some toddlers take time ma-adjust sa feel ng glasses, and the dizziness might improve once she gets used to it, pero definitely worth a follow-up appointment para ma-address ang weight issue!