What did your baby weigh at birth? 7ls, 7oz 20.5"
How long did he/she wear newborn size clothes? about 5-6 weeks
How long did he/she wear 0-3 month size clothes? It depends. She can actually still fit into some 0-3 onesies & snap shirts as well as pants. It's the sleepers that are a problem b/c they're not long enough.
How old is your baby now? She'll be 4 months next week..wow! She's also now 13 lbs, 14oz.
What size is he/she in now? Again, it depends on the brand (I find Gerber tends to run smaller for example) & what it is. She has a lot of one piece dresses that have the underpants built in & just snap closed...they're all 6 months & are quite big on her but yet she has other rompers that are 6-9 months that fit just fine. By & large, I'd say she's in 3-6 months (esp pj's) & 6 months for onesies.
I found some bodysuits that I'd forgotten about...they were 0-3 & 3 months. I figured she'd be too big for them, but they fit just fine.
Probably not the help you were looking for, but it's hard to say. Babies grow at different paces & are shaped differently so clothes can fit so differently than the "standard" or average. KWIM?