Wanted Road Bike size 56

Hi all,
I'm looking for a second hand road bike in good condition for my better half who wants to start road biking.
She'll need a size 56.
Anyone got anything suitable??
Thanks,
Colm
I know Erica, Plan is to start on the road and then maybe advance to mtb!
Thanks Caroline, 54 should do the job then.
Cheers Terry for your v astute observation :-)