9 week old chicks with rose combs- still flat?

[off-grid hen]

When will their combs start growing? I have rose comb leghorns and dominiques- 9 with Rose combs total. On 3 of the Doms, I see the tiniest bit of what looks like the spike, but the rest of the combs are completely flat, maybe slightly raised. Should they be more developed by now?

 

[debid]

My 9-week Dominique pullet has very little comb growth at all. I can see a nub for the spike at the back and that's about it. There is a breed board where you can find a whole thread on Dominiques. That would be a good place to ask.