Sparrows building nest on window door bird feeder, what do I do?

Bird potentially building a nest on our door window bird feeder, what do we do?

Hi, so we live in an apartment (building isn’t tall, average uk build) and have a special bird feeder attached to the window of our balcony door, we get a lot of blue tits, great tits etc and they get the best quality premium food so it’s very busy. This morning when my mom went to refill the feeder we noticed that our local house/tree sparrow has what we assume been building a nest inside the actual feeder cage, We are obviously delighted but worried incase she actually does use it to have her babies. What would you do in this situation? We’re more than happy to accommodate her but with it being a door that & with it being on a bird feeder we would be worried of the safety of her & her future eggs. Thanks

We are so confused on what to do, as much as we don’t mind her nesting there, it’s not the best place to be nesting. The bird feeder is in a cage,  it’s square with 2 dispensers on either side (the nest is right inbetween them) it’s attached to a window/door of a balcony as we live in an apartment.  We also get very noisy starlings every day and unfortunately that door is something that gets opened a lot 

My mom was thinking of buying a house nesting box in hopes she’d swap homes. Is this a good idea? Thanks