That’s one of the problems with small coops, you don’t have a lot of flexibility to manage issues. But you have what you have. Let’s deal with it.
How many chicks do you have? I’m not going to harass you about having some magic number of square feet per chicken or anything like that, how much room you need depends a lot on how you manage them. You can follow the link in my signature for my thoughts on that. I’m thinking more of how much roost space you will eventually need.
Silkies can’t fly, which makes them special when it comes to roosts and nests. Most chickens, including some Silkies, like to roost on the highest thing they can get to. Since you don’t want them sleeping and pooping in your nests that generally means your roosts should be higher than the nests. Some Silkies (not all, but some) are quite happy sleeping on the floor instead of on a roost at all, even a very low roost.
I don’t know if yours are using the roost yet or not. I don’t have Silkies but the normal age my brooder-raised chicks start to roost is 10 to 12 weeks. I’ve had some start a lot sooner, some later, but 10 to 12 is a good average. They will play on the roosts during the day but sleep in a group on the coop floor until they decide to roost.
Silkies can use a ramp or even jump up some even though they can’t fly. Depending on how many you have, I’d consider putting a fairly low roost across the back, maybe two at most. It’s tight, but put in a ramp or an intermediate perch or two sort of like a ladder so they can hop up there. I think that is your nest off to the right in your photo. You probably don’t need to go higher than a foot with the roost.
I don’t think you have an ideal situation but you should be able to manage it. Good luck!