Well Im new to quail and have no idea about creating a hybrid or if its even posible. I have Coturnix too and altho opinons vary on this but most seem to agree its very unlikely for a cot hen to go broody and in some rare cases that they did only went broody for a few days or so and either decided nevermind or just forgot they had went broody and left the eggs. Mine r young and I remove and gather the eggs a couple times a day as I will incubate them myself instead of hopeing one will go broody and be successful. Again this info isnt from personel experience just from the hours of research i have done on the cots so if there is a possibility to get a hybrid I think your best chances would be to incubate the eggs in a bator yourself and see what happens. Your other option is, I am pretty sure the Valley Quail do go broody and r pretty succesful at it so u could just wait til she lays a clutch and goes broody and maybe fit in as many of the cot eggs as she has room for and let her do it. The only thing is incubation period is much shorter for cots eggs then the valley's so u may have to keep an eye out toward the end of incubation in case u do hatch a hybrid or two, days early so u can remove those chicks to prevent the valley mother from leaving with the babies b4 incubation is complete on her own eggs. Good luck and if this is possible and it does work, please post pics of the hybrids as I think they would b very interesting to us all.