I had 3 children, all c sections, 2 of them premature by 6 weeks, and never needed, asked or had any help from my family, and they lived close. Not sure why you would request or need an expedited visa for a normal birth. Regardless of that, childcare is considered work, if you try to get their visas expedited for that reason, it will result in their visas being denied all together. Not a good idea.