Unfortunately, seems one thing is the law, another what is practiced!
Not saying your case is necesarily discrimination, but I would encourage to ask them why they need such info...there might be a reasonable answer...
Really if a pilot applies to a job he/she thinks can do, what does it matter if the family accepts having to move around, etc? Should not be an issue. Its a bit like asking for CV´s to include a photo...what for, who cares what people look like?? Well, I know some do