Hi Cowsden Bank
Really not what you want to find when moving an old shed! Fingers crossed they do move nearby and all survive. You may be lucky that they are just old enough that Mother didn’t desert them.
I would be inclined not to put the food too close, in case it attracts other unwanted visitors near to a new nest site. But maybe move it gradually a bit further away, if that’s what you decide to do.
Good luck with them.