I’m sorry to hear you lost so many birds from your order :(
I don’t think 4 weeks is too early for wattles on a pullet. My Welsummer (just as an example) was quick to develop, bigger than all my other girls of the same age who are different breeds, and she is definitely a pullet. She also had...
I don’t think it’s a Welsummer. I could be wrong, but I think there’s some barring on the upper wing feathers. It looks to me like some kind of hybrid, though I have no idea if it’s a Whiting True Blue.