Is one of these eggs different from the rest? (Rare Groninger Meeuw vs Frizzle bantam)

[Feather and Spice]

I was lucky to get one single Groninger Meeuw bantam hen. They're quite rare. She was with a rooster before she came to us, so we have a chance of incubating her egg.

She arrived at ours, together with some other chickens, on 22/10. Since then, a few eggs have been laid - but they could be from the Meeuw or Frizzle hen.

Please see the photo attached (with flash). The lightest egg looked different to me. I rubbed them all with a q-tip and some water, and it seems that the base colour of that egg is different. I understand Meeuw lay white eggs.
Or can one chicken lay such colour variation over a couple of days? They're very similar in weight, around 40 grams.

I know full sized Meeuws lay large eggs for their size, but I don't know whether 40 gr can get out of a bantam Meeuw. Though I have seen 36 gr from my Silkies which are smaller.

I have two options...

Either I incubate the egg tomorrow at one week old, which was laid a few days after she left her flock.

Or I wait until 12/11 latest, then a 7 day old egg will be 2 weeks after leaving the rooster. But I've been told that sometimes after transport, there is an egg in the queue that comes quickly, and then the waiting starts, which can be as long as 3-4 weeks. So there is a chance I get nothing as I understand it.

The hen is 4 years old, plus I have to find her a rooster, so I don't know how many more chances I'll get. When I look online how long a chicken will lay eggs, the answers vary wildly.

What would you do? Really appreciate your input.

 

[Egg Snatcher]

If I were you Id go ahead and incubate the eggs you have. You can do a staggered hatch which means your chicks hatch at different time. The best way to do this is to have a second incubator to put piped eggs in so the other eggs can continue to turn. Or you can let the babies hatch in the turners, I’ve done this before. I would say continue putting eggs in until the hen has been away from the rooster for 2 1/2-3 weeks. Also don’t wash the eggs. That removes the protective bloom and bacteria will get into the eggs and kill the embryo.