Long and skinny baby vs infant car seat

Robin • 🐶 Feb 18- 💍 Nov 10- 🎀 Jan 15

My 3 month old is in 6-9 month feet pajamas but can still fit in her 3 month onesies. It’s all in her legs. At the 2 month check she was 11 lbs but I’m concerned she’ll reach her car seats 32” height before the 30 lb max. Should I plan to move her up sooner than 12 mos/30 lbs?

UPDATE: I just measured my daughter and she’s around 23”