Yes, this is bad. You need to candle all of the eggs, determine which are the oldest, and mark those with a pen or pencil. Do not keep multiple ages of eggs - this will result in a staggered hatch, which cannot be done under broody. She will leave the nest 1-3 days after the first eggs hatch, leaving any remaining unhatched eggs or very young babies behind. Chances the majority of the eggs she has are either A. Non-developing or B. Began developing but died, because a Silkie can hardly fit on 6-8 eggs, much less 24, so many have likely been pushed out of under her and been chilled.
After getting her down to 4-6 eggs of the same age group, you need to either check her nest every day and remove any new eggs laid there (this is why it is important to mark the ones she will be keeping), or separate her from the flock entirely for the duration of her brooding and raising.
As I said, you will need to remove most of the eggs she currently has. If you have an incubator, you can place them in there. If not, let them cool somewhere for 12-24 hours, then throw them away.
