Lone male zebra finch

[Lone male zebra finch]

I have 3 female finches and 1 male. I wanted to put the male with them or at least one of them but they keep laying eggs! Even in the seed boxes. Can I put a male finch with any other bird? Another male zebra finch or female canary?

[Female finch with male markings?]

They could very well be related. My mother had no intention on breeding them but the pet shop said it was fine to keep a male and female together, as long as there was no nest box they wouldn't lay eggs but the female did in the seed box.

[Female finch with male markings?]

My mother's finches laid eggs about 7 months ago. There were 2 males and 2 females I thought. The 2 males got their coloured cheeks and zebra chest ages ago. Sometimes the grey female looks like she has zebra stripes under her feathers, but shouldn't she have got her colouring by now? She has no orange cheeks but has a speckled head (idk if that means anything). I posted this before and wanted to make a new post to add photos to. 

[Female or male finch?]

My mother's finches laid eggs about 7 months ago. There were 2 males and 2 females I thought. The 2 males got their coloured cheeks and zebra chest ages ago. Sometimes the gray female looks like she has zebra stripes under her feathers, but shouldn't she have got her colouring by now? She has no orange cheeks but has a speckled head (idk if that means anything).

[Incubating egg]

So my mother's zebra finches has a brood of birds. They are doing great but the mother laid an egg about 5 days ago. She wouldn't nest on it so I made a homemade incubator, which I doubted would work at all! Well I candled the egg and the embryo is moving and seems to be growing quickly. So what can I do now? Other than keeping it warm and turning it over. Do I need to play recorded finch sounds? I have egg food in case it does hatch and I'm willing to hand feed it, even if that means the early hours in the morning. Any advice you could give me?