There's certainly no harm in asking for a variation on your registration for two under-1's. There is a form you need to fill out and can be found in the Free Downloads section on this site.
I got a variation granted for two under-1's and I had only been minding for 3 months. However, mine did involve continuing the care of one child I already had and they did come and visit me because I was so new. It got turned around within 3 weeks.
Good luck
“Children are like wet cement. Whatever falls on them makes an impression.”
Bookmarks