Retroactive Refer A Friend?

I recently convinced my girlfriend to play WoW. she started on a trial, liked it. Bought a month, then decided to also buy DF.

I just now remembered that Refer-A-Friend is a thing and missed out on the benefits for us both. Is there a way to retroactively apply the referral to her account?

you can recruit before 1month iirc, but its something like that so if her account is still new you golden, just send her the link and tell her to use her currrent account