Basically you're asking if the silkie will brood the Giant eggs? If so, the answer is yep, absolutely she will. She doesn't care where those eggs came from, she'll happily set on them and raise the chicks for you. I'd imagine you could only fit 6 or so of those big eggs under her.
There are some great threads here about broody hens, I'd suggest sitting down and doing some reading. The basics I go by are....
be sure she's broody. For me, that means she's spent 2 nights in a row on the nest, and not getting off during the day except to eat/drink/take potty breaks and maybe dust bathe.
put all the eggs under her at once. Don't put a few eggs each day for several days. If you don't have enough eggs in one day, store them until you have enough to set under her. Setting them all at once means they'll all hatch at roughly the same time, and that's a good thing.
Mark the eggs you put under her. Broody hens are notorious for stealing eggs and adding to their clutch as they brood. You don't want eggs added after that first batch is placed, you'll have chicks developing at different rates and hatching a week after the first batch. Not a good thing.
Wait 21 days, and it's like magic! You get baby chicks
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When Canoe mentioned losing a bird, he was talking about a chicken continually setting on infertile eggs, or nothing at all, for weeks and weeks on end with no chicks ever coming. Most birds will give up at some point, it's really rare to lose a bird that way, but some extreme cases the hen will lose enough condition she can't recover. So, if your girl is broody, either give her eggs to hatch or break her broodiness (lots of threads here on how to do that).
