Hello

I have just taken the wheel off my wife's Dutch Style bike to repair a puncture. Simple enough. Now I have just tried to put it back on and have found a problem. On the derailleur side of the wheel, the wheel has a very deliberate place to sit but on the other side, it's almost as if I have free rein to decide where the wheel skewer should sit. I have tried locating the nut to where the paint was marked by the wheel's previous location but the chain just keeps falling when I turn the pedals. The wheel looks fairly centred but it obviously isn't.

Any advice is greatly appreciated!

Thanks in advance.