Something wrong with my chicks?

[Barbeque]

My chicks are 3 weeks old now, and they are still very small. Like, the size of my palm! Noo, smaller.
Why are some chicks that are 4 weeks like, the size of a foot?
And also, I'm going to visit family in Vegas June 9-29, can I put them in a chicken tractor before then, after then, or should I get my dad to do it sometime while I'm gone? I prefer it to not be the latter of the three, but oh well. When can chicks go outside? It'll be 85-97 degrees then (based on averages on weather.com)

 

[teach1rusl]

What breeds do you have, and are some of them bantams? Bantams are quite small. If you're leaving June 9 and your chicks are three weeks now, I'm sure they can move to their "adult" coop before you leave. If the weather is warm/hot, they should be able to go to the new coop in another 2-3 weeks, so they'll have time to become familiar with it before you leave.

 

[Barbeque]

Are Frizzles bantams?
I know I have two Golden Sebrights, they are bantams, right?
I have a Frizzle, two BRs, two Golden Sebrights, a Silver Laces Polish chick, and a Wyandotte.
Got them Monday, and she said they were 2 weeks old.

 

[LeBlackbird]

most of those are petite breeds, so that's probably why. Or they are younger than she thinks

 

[teach1rusl]

So some of them are tiny (seabrights, frizzle), but the BR and the wyandotte are a little bigger, right?? That would be normal. I'm not sure about polish, although they are lighter bodied birds. Anyhow, that's why they are of such different sizes. Your bantams may only end up weighing 2 lbs soaking wet as adults, while your BR may weigh 6lbs...